nautilus hits SIGABRT: sidebar->go_to_after_mount_slot == NULL

This crash occurs when trying to open, (mount) more than 1 internal partition from the same nautilus window

Test case: have 2 or more available partitions to mount
Open nautilus, click on one in sidebar - it mounts/opens fine
Click on a 2nd one, nautilus hangs, then crashes

from xsession-errors
ERROR:nautilus-places-sidebar.c:1885:open_selected_bookmark: assertion failed: (sidebar->go_to_after_mount_slot == NULL)

attached small vid
This is on todays iso, upsated, in a live session. See the same thing on a real install & have for some time now in 12.10

ProblemType: Crash
DistroRelease: Ubuntu 12.10
Package: nautilus 1:3.5.1-0ubuntu4
ProcVersionSignature: Ubuntu 3.4.0-3.8-generic 3.4.0
Uname: Linux 3.4.0-3-generic x86_64
ApportVersion: 2.1.1-0ubuntu2
Architecture: amd64
CasperVersion: 1.317
Date: Fri Jun 1 20:29:04 2012
ExecutablePath: /usr/bin/nautilus
GsettingsChanges: org.gnome.nautilus.window-state geometry '800x550+65+24'
LiveMediaBuild: Ubuntu 12.10 "Quantal Quetzal" - Alpha amd64 (20120601)
ProcCmdline: nautilus -n
ProcEnviron:
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
Signal: 6
SourcePackage: nautilus
StacktraceTop:
 raise () from /lib/x86_64-linux-gnu/libc.so.6
 abort () from /lib/x86_64-linux-gnu/libc.so.6
 g_assertion_message () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
 g_assertion_message_expr () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
 ?? ()
Title: nautilus crashed with SIGABRT in raise()
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo
XsessionErrors: (compiz:7826): GConf-CRITICAL **: gconf_client_add_dir: assertion `gconf_valid_key (dirname, NULL)' failed