Hi Sion,
I listened to the file, and it sounds fine. The only thing is that you were probably tuned slightly to high, giving a too low audio pitch (on USB mode that is) so that the carrier frequency is outside the capture range of RASCAL (1400-1800Hz). If you have a program that can make a waterfall display like spectran or MixW, you can try running that parallel to RASCAL and try centering the signal on 1600Hz, best is to do this during the transmission of AX.25 flags between the frames since these give discrete spectral lines spaced 150Hz and the strongest one is the carrier which should be around 1600Hz. RASCAL may sometimes gives false sync indications with strong signals since it then tries to lock onto one of the sidebands.
hope that helps!
73
Wouter Jan Ubbels PE4WJ