gitk (or tcl/tk) slow to start?

Every time I run gitk when I didn't use it for a while, it takes a long time to start (more than 30 seconds) with no visible cpu load. I tried to strace it, and the result shows that the time is spent stat()ing my whole /usr/lib directory:

  ...
  stat("/usr/lib/libelf-0.131.so", {st_mode=S_IFREG|0755, st_size=87496, ...}) = 0
  stat("/usr/lib/libungif.so.4", {st_mode=S_IFREG|0755, st_size=2444, ...}) = 0
  stat("/usr/lib/libtiff.so.3.8.2", {st_mode=S_IFREG|0755, st_size=360268, ...}) = 0
  ...

Is this expected?  Anything that can be done to avoid it?

[This is using a new git version (1.7.1), but it's an old OS (Fedora 7), so maybe tcl/tk is buggy?]