Machine is Ultra 60, I am connected using ssh -X from Fedore Core 5. It does not happen when I am logged directly at desktop using JDS.
uname -a on Sparc machine:
SunOS ganymed 5.10 Generic_118833-20 sun4u sparc SUNW,Ultra-60

uname -a on Linux Fedora Core 5 machine I am connected from:
Linux d-eprg05-75-221 2.6.17-1.2157_FC5 #1 Tue Jul 11 22:55:46 EDT 2006 i686 i686 i386 GNU/Linux

I applied latest J2SE Recommended patches on Solaris 10. I will attach log from JVM crash.

It does not happen with latest Mustang build 95.