tracks not playing audio till plugs are reinserted
 

When I re-open this particular session, any tracks with plug ins (mostly RTAS plugs as I am TDM dsp limited) do not play audio till I re-insert the plug ins.

whats up with this?

and.. is there any reason for me to make sure i am running the most recent version of 5.1 software? is maybe causing this? I hate to upgrade software unloess I have to. Would upgrading to the latest update of TDM software fix this?

I am running Pro Tools 5.1 TDM on a QS 867 Mac running os9.2.2 with a d24 card and a single dsp farm card.