Subtitles disappear with full screen
 

My version of BSplayer is 2.53.1034
I have upgraded to windows 7, 64 bit
I set both primary and secondary subtitles on a minimized screen - including dragging to full size - they are fine.

When I go to full screen they disappear.
Please help

Additional information
CPU Intel i7 930
Video card Nvidia geforce GTS 250
Subtitles - done by myself then finalized in Subtitle Workshop

I have resetup my old desktop as a check - windows xp pro. sp3
Celeron 1.7 CPU. Video card Nvidia GeForce 6200
The 2.53.1034 edition works correctly. Subtitles display correctly.

Does anyone else have this problem of one or both subtitles disappearing when using windows 7 64 bit?