Yes, there are conflicts, as Chris Green has pointed out.
No, we do not have a full list, because RedHat 6.0 only hit the net
a few days ago, and it not yet officially released (10 May as I recall).
And , of course, the new 2.2.5/6/7/... kernel is changing weekly.
The long awaited NFS improvements have finally reached Beta test.
The new glibc has several known conflicts with important software packages.
We can expect further rapid change.
I would certainly welcome any and all expert feedback.
I think we can not yet offer Fermilab RedHat 6.0/Kernel 2.2 support,
for the reasons outlined above.
In fact, the RedHat 5.2 testing is not even complete.