"Caught signal 11 (Segmentation fault). Server aborting"

So far I've only been able to duplicate this when tunneling Eclipse. I 
tried writing a simple java program that creates a JFrame window but 
could not replicate the crash with anything smaller (sorry!). The 
problem exists in the two versions I tried: Eclipse 3.6 and 4.2.

Although the error message pops up, Cygwin/X doesn't actually terminate 
until the error window that reports the segfault is closed. X continues 
to work if I ignore it, however all of the newly created windows do not 
have any titlebars or frame borders.

This problem does NOT occur when running with either a root window or 
with the '-rootless' option.

I've attached the XWin backtrace.