(In reply to comment #12)

After several backtraces like in the previous comment there is the following
one:

(EE)
[mi] Increasing EQ size to 1024 to prevent dropped events.
[mi] EQ processing has resumed after 433 dropped events.
[mi] This may be caused my a misbehaving driver monopolizing the server's
resources.
(II) AIGLX: Suspending AIGLX clients for VT switch
(EE)
(EE) Backtrace:
(EE) 0: /usr/bin/X (OsLookupColor+0x136) [0x80b6a56]
(EE) 1: ? (?+0x136) [0xb77bd541]
(EE) 2: /lib/libc.so.6 (__GI_memcpy+0x46) [0xb72e34a6]
(EE) 3: ? (?+0x46) [0x9e76e3e]
(EE)
(EE) Segmentation fault at address 0x0
(EE)
Fatal server error:
(EE) Caught signal 11 (Segmentation fault). Server aborting
(EE)
(EE)
Please consult the Fedora Project support
         at http://wiki.x.org
 for help.
(EE) Please also check the log file at "/var/log/Xorg.0.log" for additional
information.
(EE)
(EE) Server terminated with error (1). Closing log file.