Do you have any good autosaves?
Thank you for the clarifying question. I had a lot of issues with autosave so it has been turned off due to PP intermittent crashes. However, when I refer to versions I intended to say that I did a "save as" every few days and named the file differently. So the earlier versions of my project file did work fine but now when I open them up I get the dialog that the project must be converted and upon conversion they are corrupted (the dialog also says that the original file will not be touched and PP creates a new file). I have many earlier project versions and I have opened up at least 5. They all exhibit this behavior and I know that they worked fine before (I wrote out a DVD and that didn't have these issues). One other finer detail is that it is the mpeg files where the audio seems to have been most corrupted. I haven't checked the wav files to validate that they are all intact.
Were those Save_As Projects also created in PrPro 5.5, or in an earlier version?
A PrPro CS 5.5 Project should not require conversion, like one from say, CS 4 would.
Yes, all file "save as" were in the same version of PP and the version of PP has not changed. Tthat's why it's perplexing that PP is giving this dialog for a need to convert (I never recieved this dialog before). The file(s) are a year old so maybe it's a system date issue where it doesn't recognize the file for some odd reason. These project file versions were last saved in May, June and July of 2011.