session shutting down PT

[queenstonmusic]

The answer to my dilemma might be in this question, but I'd love to hear from the more knowledgeable PT users out there. Here's the scenario;
I've recorded a session @ my studio using a G5 Mac Pt 7.3.1./10.4.8.

I then took the HD home and worked on the session on my intel Macbook Pt 7.3.1/10.4.9 @ home.

When I took the session back to the studio (Pt 7.3.1/10.4., however, Pt will not open the session and quits unexpectedly whenever I attempt to open it.... Is it possible/probable then that the answer is simply updating my studio Mac to version 10.4.9 from 10.4.8?
.....btw I thought I had updated my G5 to 10.4.9 and I was shocked to find out that it's actually @ 10.4.8, just as I was half way out the door...
......before I discovered this I had simply opened a new session and imported the tracks that I wanted to use as a workaround