Synchronisation problems synthfont/Sonar

This problem just popped up after I had to rebuild my system recently.

I have been renedering midi drum tracks using Sonar 4 and BFD, then I have rendered the rythm parts using Synthfont.

Up til now no problem, but suddenly now the Synthfont parts don't sync with the Sonar/BFD parts, the synthfont tracks are up to two beats slow!

If I play the same track in SOnar and record in AA it syncs perfectly - but it is very slow (real time)!

I have checked the orginal file -130bpm, SOnar setup - 130bpm, BFD - 130bpm, Synthfont in and out 130 bpm, but the final wav looks like about 128bpm.

This may be a setting I have forgotten to adjust - does anyone have any idea where I should start looking?