libvirt takes to long to start and kvm guests not always start

Binary package hint: kvm

I have three hosts running ubuntu 8.04.3 amd64 and i using ubuntu-virt ppa (https://launchpad.net/~ubuntu-virt/+archive/ppa) i updated kvm and libvirt to more recent versions.
Recently in one of the hosts i started to have problems: libvirt-bin takes too much to load after boot (several minutes) and randomly most of my guests don't start up.
When i start a guest using virsh after more than 10 seconds it fails and i get this on the logs:
libvirt error : internal error Timed out while reading console log output

After some googleing i found this: http://<email address hidden>/msg11996.html basically it says kvm 84 (the same version that is on the ppa) just takes too long to start a guest.

So i removed kvm 84 from the ppa and installed kvm 62 from the hardy repos - i kept the newer kvm kernel modules and libvirt, and all the problems disappeared - libvirt-bin loaded right away and all the guest started all the time.

HOST:

$ uname -a
Linux core.eufinity.com 2.6.24-24-server #1 SMP Fri Jul 24 22:44:54 UTC 2009 x86_64 GNU/Linux

$ dpkg -l | grep 'libvirt\|kvm'
ii kvm 1:62+dfsg-0ubuntu8.2 Full virtualization on x86 hardware
ii kvm-source 1:84+dfsg-0ubuntu12.1~rc5ppa1 Source for the KVM driver
ri libvirt-bin 0.6.1-0ubuntu5.1~rc1ppa1 the programs for the libvirt library
ii libvirt0 0.6.1-0ubuntu5.1~rc1ppa1 library for interfacing with different virtu
ii python-libvirt 0.6.1-0ubuntu5.1~rc1ppa1 libvirt Python bindings

$ cat /proc/cpuinfo
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 23
model name : Intel(R) Xeon(R) CPU X3350 @ 2.66GHz
stepping : 7
cpu MHz : 2666.613
cache size : 6144 KB
physical id : 0
siblings : 4
core id : 0
cpu cores : 4
fpu : yes
fpu_exception : yes
cpuid level : 10
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx lm constant_tsc arch_perfmon pebs bts rep_good pni monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr sse4_1 lahf_lm
bogomips : 5336.14
clflush size : 64
cache_alignment : 64
address sizes : 36 bits physical, 48 bits virtual
power management:

(..)

$ cat /proc/meminfo
MemTotal: 8198216 kB

(..)

GUESTS:

A combination of ubuntu (7.10 and 8.04.3) and win2k3 server guests with several memory and cpu configs.