Problems with ProTools 7.4

[VivianDarkbloom]

Hi everyone, I've been working on a ProTools project for a few months using LE 7.4 and the Mbox2, and have about twenty MIDI tracks in play. Recently I have been encountering several problems that make work all but impossible.

1)DAE Error 9060 that allows no playback on my original file or any of the backups.

2)An unexpected shutdown when saving a project, because ProTools is critically low on memory, even though I have ~3.3 GB RAM and this project only uses 2.3 at maximum. (And after which the file usually shows one of those "end of stream encountered" dealios and I have to go to a backup file. I have Windows Vista Home Premium if that's any help.)

3)A random disappearance of all my virtual instruments from all the tracks. I don't lose the MIDI data but I have to manually supply each track with its former instrument (I use three different software packages from SampleTank). If I had effects on those tracks, of course they are lost too. This often happens after I try to duplicate a track.

Any feedback would be appreciated! I'm desperate!

Krista