OK folks, I'm stumped. Help? (Note: seasoned unix admin, not newbie)

Situation:

OLD SERVER: RHEL4. All logins and shells and use of /etc/profile works like a charm, as expected. All the necessary $PATH and other variables get set the way we need.

NEW SERVER: RHEL5. All logins work as expected, with one very odd exception: If the user is logging in via X, *and* if the users' shell is KSH, then it appears that /etc/profile is not being used.

PURPOSE: "New server" going to be replacement for "old server". Additionally, user login directories are automounted, so they are 100% the same between the two hosts. User accounts in question do not have private profiles, kshrc's, or anything like that.

MORE FUN: On the new server, if I do any type of standard terminal-based login (any shell applies), the /etc/profile mechanisms seem to work great. even for KSH users-- no problems.

TO REITERATE: Again, on the new server, if the users log in via X (we have lots of X-based apps... ugh) - their $PATH set in /etc/profile works like a charm if they use any other shell- until I come to ksh. When it's a ksh user, the only $PATH set is the absolute bare minimum and in our situation, tons of programs will not function because environment variables and paths are not set.

SO--- If logging in via X, and user has KSH-- how the heck can I enable /etc/profile? X and any other shell WORKS, and ksh (if not via X) works.

I am totally stumped, and haven't been able to figure this out. It makes no sense either, since other shells behave, and also since any other login type ALSO behaves, even with ksh.