Rhythmbox crashes while loading music library "(insufficient resources)"

When I try to start Rhythmbox it crashes while loading the music-library. Running Dapper Beta 2 on Fujitsu Siemens Amilo A 7640 (Turion 1,8).
My Terminal output:
stevi@ubuntu:~$ rhythmbox

(rhythmbox:7289): Rhythmbox-WARNING **: Unable to start mDNS browsing
The program 'rhythmbox' received an X Window System error.
This probably reflects a bug in the program.
The error was 'BadAlloc (insufficient resources for operation)'.
  (Details: serial 4952 error_code 11 request_code 53 minor_code 0)
  (Note to programmers: normally, X errors are reported asynchronously;
   that is, you will receive the error a while after causing it.
   To debug your program, run it with the --sync command line
   option to change this behavior. You can then get a meaningful
   backtrace from your debugger if you break on the gdk_x_error() function.)
----------------------
stevi@ubuntu:~$ gdb rhythmbox
GNU gdb 6.4-debian
(...)
This GDB was configured as "i486-linux-gnu"...Using host libthread_db library "/lib/tls/i686/cmov/libthread_db.so.1".

(gdb) handle SIG33 pass nostop noprint
Signal Stop Print Pass to program Description
SIG33 No No Yes Real-time event 33
(gdb) run
Starting program: /usr/bin/rhythmbox
[Thread debugging using libthread_db enabled]
[New Thread -1226606368 (LWP 7434)]
[New Thread -1255998544 (LWP 7439)]
[New Thread -1264391248 (LWP 7440)]
[New Thread -1265198160 (LWP 7441)]
[New Thread -1273590864 (LWP 7442)]

(rhythmbox:7434): Rhythmbox-WARNING **: Unable to start mDNS browsing
[Thread -1265198160 (LWP 7441) exited]
[Thread -1273590864 (LWP 7442) exited]
[New Thread -1282012240 (LWP 7444)]
[Thread -1282012240 (LWP 7444) exited]
The program 'rhythmbox' received an X Window System error.
This probably reflects a bug in the program.
The error was 'BadAlloc (insufficient resources for operation)'.
  (Details: serial 4952 error_code 11 request_code 53 minor_code 0)
  (Note to programmers: normally, X errors are reported asynchronously;
   that is, you will receive the error a while after causing it.
   To debug your program, run it with the --sync command line
   option to change this behavior. You can then get a meaningful
   backtrace from your debugger if you break on the gdk_x_error() function.)

Program exited with code 01.
----------------
Tell me if you need some other output. This is my first time reporting a bug and I'm unsure which commands to enter. (I think it's not the same problem as bug Bug #40565)