Sync shifting going from FCP to STP

When I send an aduio segment in the timeline from FCP to STP using -send to: soundtrack pro audio file project-
I can see my audio shifting in the FCP timeline as it opens STP, I do nothing on STP, I go back to FCP and indeed it has shifted. I have read the STP manual but it does not adress this problem. Any suggestions? Should I reinstall?

Using:
FCP 5.0.4
QT 7.1.1
STP 1.1