Upgraded to R14.1.5 which also brought in tde-cdbs and cdbs. Rebooted. Firefox, Kmail, Konsole, KPDF worked fine.
Switched to desktop 4, Started Steam, mouse cursor changed to Steam cursor, system froze solid. CapsLock, NumLock, mouse cursor, ctrl-alt-del, and ctrl-alt-F1 all did nothing. Fan speed did not change. (I have never seen this before in more than a decade of TDE and Steam.)
Powered cycled and tried again. This time Steam worked.
No bug filed (yet).
Please reply to this thread if you encounter anything similar.
--Mike