SoundBlaster Audigy 2 NX USB 2.0 behind USB 2.0 hub = strange things happen

Like described in summary strange things happen. The problem is that sometimes the soundcard works, but its not very often, and never if it is already plugged in while booting. Following things happen:
- the soundblaster says its connected to computer (no red LED)
- Kaffeine says "Überprüfen Sie, ob ein anderes Programm bereits PCM benutzt: snd_pcm_open() schlug fehl: -2: no such file or directory", translated in english: "Check, if another application already uses PCM: snd_pcm_open() failed: -2: no such file or directory"
- Amarok crashed (crash report see below) after showing the message "cannot load xine drivers"
- alsamixer just says
Card: USB Device 0x46d:0x8ad
│ Chip: USB Mixer
│ View: [Playback] Capture All
│ Item: Auto Gain Control [Off]
instead of showing any channel of this 7.1 soundcard

Its only behind the usb hub, if i connect it direct it works, also under windows it works behind the usb hub. a usb hard disk or a keyboard behind the usb hub also work with linux. I use Kubuntu 6.10 with all updates and KDE 3.5.6

message log / dmesg if i disconnect and connect the soundblaster:
Feb 14 23:57:23 infinity kernel: [17204871.632000] usb 4-2.1: USB disconnect, address 4
Feb 14 23:57:26 infinity kernel: [17204874.904000] usb 4-2.1: new high speed USB device using ehci_hcd and address 8
Feb 14 23:57:26 infinity kernel: [17204874.996000] usb 4-2.1: configuration #1 chosen from 1 choice

Amarok Console:
infinity@infinity:~$ amarokapp
kdecore (KAction): WARNING: KAction::insertKAccel( kaccel = 0x80983a0 ): KAccel object already contains an action name "play_pause"
QLayout "unnamed" added to QVBox "unnamed", which already has a layout
kdecore (KAction): WARNING: KAction::insertKAccel( kaccel = 0x80983a0 ): KAccel object already contains an action name "play_pause"
QLayout: Adding KToolBar/mainToolBar (child of QVBox/unnamed) to layout for PlaylistWindow/PlaylistWindow
--> here the message comes with "cannot load xine drivers", after clicking ok it continues:
STARTUP
Amarok is crashing...
Running: gdb --nw -n --batch -x /tmp/kde-infinity/amaroko0StIb.tmp /usr/lib/amarok/amarokapp 15289
Running: file /usr/lib/amarok/amarokapp
1.4.5 [___stripped][validity: 0.86][frames: 42][xine]
infinity@infinity:~$

Amarok Crash Report:

======== DEBUG INFORMATION =======
Version: 1.4.5
Engine: xine-engine
Build date: Feb 2 2007
CC version: 4.1.2 20060928 (prerelease) (Ubuntu 4.1.1-13ubuntu5)
KDElibs: 3.5.5
Qt: 3.3.6
TagLib: 1.4.0
CPU count: 1
NDEBUG: true
==== file /usr/lib/amarok/amarokapp =======
/usr/lib/amarok/amarokapp: symbolic link to `/usr/bin/amarokapp'

==== (gdb) bt =====================
Using host libthread_db library "/lib/tls/i686/cmov/libthread_db.so.1".
[Thread debugging using libthread_db enabled]
[New Thread -1250740560 (LWP 14931)]
[New Thread -1275724896 (LWP 14934)]
[New Thread -1256039520 (LWP 14933)]
0xffffe410 in __kernel_vsyscall ()
#0 0xffffe410 in __kernel_vsyscall ()
#1 0xb6b8a34b in __waitpid_nocancel () from /lib/tls/i686/cmov/libpthread.so.0
#2 0x0804d211 in Amarok::Crash::crashHandler ()
#3 <signal handler called>
#4 0xb44b8b08 in xine_set_param () from /usr/lib/libxine.so.1
#0 0xffffe410 in __kernel_vsyscall ()
No symbol table info available.
#1 0xb6b8a34b in __waitpid_nocancel () from /lib/tls/i686/cmov/libpthread.so.0
No symbol table info available.
#2 0x0804d211 in Amarok::Crash::crashHandler ()
No symbol table info available.
#3 <signal handler called>
No symbol table info available.
#4 0xb44b8b08 in xine_set_param () from /usr/lib/libxine.so.1
No symbol table info available.
==== (gdb) thread apply all bt ====
Thread 3 (Thread -1256039520 (LWP 14933)):
#0 0xffffe410 in __kernel_vsyscall ()
#1 0xb6b893fb in __read_nocancel () from /lib/tls/i686/cmov/libpthread.so.0
#2 0xb69c32a8 in vio_read () from /usr/lib/libmysqlclient.so.15
#3 0xb69c331e in vio_read_buff () from /usr/lib/libmysqlclient.so.15
#4 0xb69c464c in net_realloc () from /usr/lib/libmysqlclient.so.15
#5 0xb69c480d in my_net_read () from /usr/lib/libmysqlclient.so.15
#6 0xb69be5a8 in net_safe_read () from /usr/lib/libmysqlclient.so.15
#7 0xb69bec25 in cli_read_rows () from /usr/lib/libmysqlclient.so.15
#8 0xb69bdad4 in mysql_real_query () from /usr/lib/libmysqlclient.so.15
#9 0xb6997775 in mysql_query () from /usr/lib/libmysqlclient.so.15
#10 0xb7ab0d03 in MySqlConnection::query () from /usr/lib/libamarok.so.0
#11 0xb7ab7a1d in CollectionDB::query () from /usr/lib/libamarok.so.0
#12 0xb7b00eb4 in CollectionDB::uniqueIdFromUrl () from /usr/lib/libamarok.so.0
#13 0xb7bf5fc8 in MetaBundle::setUniqueId () from /usr/lib/libamarok.so.0
#14 0xb7bf61e8 in MetaBundle::setUrl () from /usr/lib/libamarok.so.0
#15 0xb7d3b4df in MetaBundle::XmlLoader::newAttribute ()
   from /usr/lib/libamarok.so.0
#16 0xb7d3b3e3 in MetaBundle::XmlLoader::startElement ()
   from /usr/lib/libamarok.so.0
#17 0xb7caec6e in MyXmlLoader::startElement () from /usr/lib/libamarok.so.0
#18 0xb64878c0 in QXmlSimpleReader::parseElement () from /usr/lib/libqt-mt.so.3
#19 0xb6488a20 in QXmlSimpleReader::parseContent () from /usr/lib/libqt-mt.so.3
#20 0xb6487a22 in QXmlSimpleReader::parseElement () from /usr/lib/libqt-mt.so.3
#21 0xb6488ca2 in QXmlSimpleReader::parseBeginOrContinue ()
   from /usr/lib/libqt-mt.so.3
#22 0xb648919a in QXmlSimpleReader::parse () from /usr/lib/libqt-mt.so.3
#23 0xb7d3a3fb in MetaBundle::XmlLoader::load () from /usr/lib/libamarok.so.0
#24 0xb7cae29a in UrlLoader::loadXml () from /usr/lib/libamarok.so.0
#25 0xb7cb4700 in UrlLoader::doJob () from /usr/lib/libamarok.so.0
#26 0xb7d30809 in ThreadManager::Thread::run () from /usr/lib/libamarok.so.0
#27 0xb61ae101 in QThreadInstance::start () from /usr/lib/libqt-mt.so.3
#28 0xb6b83504 in start_thread () from /lib/tls/i686/cmov/libpthread.so.0
#29 0xb67c651e in clone () from /lib/tls/i686/cmov/libc.so.6
Thread 2 (Thread -1275724896 (LWP 14934)):
#0 0xffffe410 in __kernel_vsyscall ()
#1 0xb6b86a8c in pthread_cond_timedwait@@GLIBC_2.3.2 ()
   from /lib/tls/i686/cmov/libpthread.so.0
#2 0xb449ddff in _x_metronom_init () from /usr/lib/libxine.so.1
#3 0xb3f5f45c in ?? ()
#4 0xb3f5f464 in ?? ()
#5 0x084860d8 in ?? ()
#6 0xb3f5f45c in ?? ()
#7 0x0006e39e in ?? ()
#8 0x00000000 in ?? ()
Thread 1 (Thread -1250740560 (LWP 14931)):
#0 0xffffe410 in __kernel_vsyscall ()
#1 0xb6b8a34b in __waitpid_nocancel () from /lib/tls/i686/cmov/libpthread.so.0
#2 0x0804d211 in Amarok::Crash::crashHandler ()
#3 <signal handler called>
#4 0xb44b8b08 in xine_set_param () from /usr/lib/libxine.so.1
#0 0xffffe410 in __kernel_vsyscall ()

==== kdBacktrace() ================