FC4 - Can run Xwinodws on remote Fedora/RH but not Solaris9

[ed]

I just upgraded my machine to FC4 and am having a few issues. I
administer some Solaris9 servers running NetBackup. In FC3, I could
either SSH or telnet to the Sun machines, issue an "export
DISPLAY=myipaddress:0.0" and then start a Java GUI. 

In FC4 I get "Cannot connect to display". To assure myself that I was
not imagining anything, I tried xclock with the same result. I also
administer about 12 RH AS3 & 4 servers but did not have the same
problem. 

I'm wondering if this has anything to do with Java or the version of X-
Windows.

If anyone has resolved this issue, please let me know what you did.

Thanks,
Ed