Have you switched to a different brand of disc lately ?
This can be a problem sometimes… as cheapo disc do not burn well… nor are they easily red by stand-alone-players. Use Verbatim or TY discs only.
Update to Ver 4080 and try again.
I had no problems ripping / burning Beowulf (Region 1 Win XP) using FAB Plat 4065 beta.
Hope this helps…