No sound here too after upgrade to 2.6.10. This is a x86_64 version. My sound is internal AC97. Just tried the last 2.6.9 kernel and sound plays fine. Looks like lots of reports on this are coming in:
https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=144879
I just added a "me too."
-gene
Just discovered my problem with sound in 2.6.10 can be fixed by un-muting some slider buttons in kmix. Other (real) sound problem now seem to be consolidated in this bug report:
https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=144742