I have been using Liquid 1.9 and 2.0 RC for quite some time. I recently have been using PE 6 2.3.3 beta. I can restore Timeriffic using Titanium Backup but can't restore the data from Timeriffic that was saved under the Liquid ROMs.
Likewise my homepage arrangement for LauncherPro that was backed up with LP's homepage backup, will not restore on PE6 beta. (It still restores fine on Liquid.)