Artifacts, burned in pink colored lines

Question

Hi. At my studio we have been having a big problem on a select few computers with Photoshop CS6 and earlier versions. When we open a file sometimes, randomly there will be a streak of color in the file that we did not make. Once this appears, it is burned into the layer and the only way to get rid of it is to paint it out or clone it out. This isn't a good solution for our studio, so we've been making back ups of every file and saving in iterations. so when it happens, we open up an older version, drag out the untainted layer and delete the layer Photoshop messed up. Problem is, this is troublesome because some of the comps we work with are like 5 gigs and larger. Sometimes it's a pixel wide line, other times it is really think. Sometimes it's pink, sometimes it's another color. It seems to be a very random issue that we can't pinpoint. I attached an image below to give an example.
So does anyone know the solution to this problem? We've tried switching videocards, ram, ect and nothing has worked. We have yet to disable OpenGL, but we use rotate canvas a lot so we don't want to go that route if possible.
Thanks for your time and help

Answer 1

I went over the problem again with our employee. He said he can grab a file off the server, open it and it will be messed up. He'll close it without saving it. Have someone else copy the same file off that server, they open it and the file is completely fine.  Now, the problem is this is happening on open and ALSO on saves. So a file can be fine, work in it, save, still looks fine. Reopen that file and not there's an artifact somewhere. Take that same saved file,  give it to another PC and that artifact is there. So the fact it happens on open for one computer and not another is weird. The fact is happens on save and can't be seen until reopen, but that saved reopen file it gets burned in also sucks. It happening on two computers of different OSes is bizarre. The Win7 PC was CS6. The Mac OS computer it happened one time on has CS5
Station Two
to be clear, we don't save files directly to a server or work off of the server (local saves are much quicker). We save them locally and then copy them up to the network so other people can grab the files if needed. IFiles are getting messed up before ever touching the server and also once through FTP. This is happening to files saved locally mostly, not just ones grabbed off a server though it being grabbed off the server will be messed up for that one user, but not others. So a file can be fine, opened on that one computer and it is messed up. The original file can be opened up on another computer and opens up fine. Same file, from the same source, two different results. So that makes us think the server isn't the culprit.
Our FTP files never go through the server. It's two completely different routes of file transfer. Our server is basically a local server and the FTP is for giving files to people who aren't local. So what happens is the local file is copied to the FTP and/or the server. The files are NOT copied from local to the server, then from the server to the FTP. Files either got local to the FTP or local to the Server. The server at that point never touches a file that gets sent to the FTP. The server for the most part never touches a file until it's done for the most part and these issues happen way before a project is done.
None of the files are flattened PSDs. They're all full layered.
We've had PSD files just be straight up corrupt before and not open, but we've always know why it happens. This one seems isolated to two computers running two different OSes and can happen to files that computer never even saved. I wish it happened more frequently because it would be easier to identify the issue, but it doesn't.
Going to have Photoshop reinstalled and just hope that magically fixes the issue.