CPT files getting corrupted, seem to also corrupt Windows font(s)

My computer is an i7 running Windows 7 Pro 64-bit. I do the graphics for our real estate business; pretty straightforward stuff that's typically a JPG background with text boxes and maybe a few other JPEGs in the foreground, etc. Nothing fancy.

I've been using X4 for years. On (thankfully) VERY rare occasions, I've had Photo-Paint lock up while working, and when I restarted it and tried opening the file, it would lock the program completely. I could no longer open the file at all, no matter if I rebooted, etc. My only option was to either restore the file or reconstruct it.

The first time this occurred, I happened to notice that the fonts in other Windows programs didn't look right. After a bit of guesswork and trial and error, I found that some Windows core fonts (like Times New Roman) were either nonfunctional or missing completely. I reinstalled those fonts and all worked fine again. HOWEVER, the corrupted .cpt file was still corrupt, permanently.

It seems that if a freeze occurs with file(s) open, the program can corrupt not only those files, but actual font(s) in Windows as well. Unless the fonts are reinstalled, the program stays in a "corrupt state" during which any files you save will be permanently corrupted too!

While in this state, I opened CorelDraw to look at a .cdr file I'd recently saved. I made the mistake of saving it, and it too got corrupted. Luckily I had a backup.

Recently I had about 5 .cpt files open. Photo-Paint locked up suddenly, and the mystery corruption happened again. This time it appeared to have corrupted several files. The problem is that you don't know they're corrupt until you try to open them, at which point the program locks up hard.

I thought I'd found all of the possible corrupt files, and either restored known good versions, or replaced them from scratch. However, a file that I'd thought was OK now locks my Corel when opened. My fear is that there's another corrupt file that I'm opening without realizing it. My bigger fear is that an underlying problem is causing this, and that it will randomly bring about the corruption of my files without any way of knowing how or when.

I back up every day, both to a local drive and offsite via CrashPlan, but some of the corrupted files were backed up in their corrupted state, so that wasn't helpful. Plus, if they're just going to get corrupted again, it's a moot point.

So far, it's only a very few files that have been affected, but not knowing the true cause, and a reliable fix, has me gravely concerned.

Has anyone else experienced a situation like this?

Any and all advice would be MOST appreciated!

Thank you.