Please help me overwrite my files! (Cross-posted)

Hey everyone, sorry for being a delinquent poster who only cross-posts help messages, but I'm desperate.

I use the same version of Photoshop (CS) here at home as well as on my workstation. Now the thing is, I have a huge project which takes up 20 PSD files, which I save a copy each at home and at work. Now when I open the copies at work, all my changes show up, great. But when I open the same files at home to work on them (which is happening more and more often, WTF XP), NONE of the changes I'd put in them appear - each PSD reverts to the way it was more than a week ago! For starters, it shows up with a different font instead of Arial (the default font for all the text in the files). And, all the stuff I'd erased a day before have re-appeared. What peeves me even more is that I actually keep saving each change as I go.

So what gives? Is there any way I can fix it? It's never happened to me before, so I'm stumped.

Thank you very much for any and all help. I'm getting desperate because every second spent re-doing each previously changed bit of data means moving a second backward from finishing this project.

Again, if this isn't allowed, I'm really sorry and the mods may delete this. Thanks again.