Every now and then my monitor will do something weird. It’s very visual, but I will try to explain. It looks like the screen is going away from me, zooming out. Then it comes back and acts normal for a few hours. I have a de-gauss button, which when pushed will mess up the screen in a wiggly and smeary colorful sort of way. This is not what it looks like when it does its “weird” thing. This has been happening for about a month. Is the monitor about to die? Has anybody ever seen this phenomenon?
I’d recommend taking it to a shop. Definitely sounds like a warning sign. Or, if it’s a cheap or old monitor, just get a new one. Dell sells refurbished 21" Sony’s for pretty cheap these days. 
Dolores Claiborne, look at the back of it, find the date of manf & report back to me here. ALso, when you are back there make sure that cable is plugged in real snug to the computer.
Hypoglycaemia?
Muffin:
I don’t think the problem is with Dolores. This sounds like a completely crazed monitor, possibly a hardware fault.
Dolores:
If it bugs you, I’d just get a new one. As has been said above, you can get a functional old one cheaply if you just shop around a little. An out of date monitor, unless you get a real antique, has the same functionality as a new one. 
Just a thought. I recall seeing something very similar to what you’re describing in mud loggers’ trailers on drilling locations where the trailer was run off a generator with no power conditioning. The power would fluctuate, but not drop enough to reboot the PC. That could, I suppose, happen at your home. If that were the case a UPS (Uninterruptible Power Supply - basically a battery backup/surge suppressor) might help.
FWIW, I’ve had more monitors fail than any other hardware component. Right now I’ve got a Nanao sitting by the front door waiting for heavy trash day.
The best free resource on the Net for such consumer electronics problems is the sci.electronics.repair
FAQ by the amazing Samuel Goldwasser. See
http://www.repairfaq.org/
The OP’s problem is in the CRT section, 9.32. Fixable by a competent pro. (If you know where to find one.) I’m pretty good at this stuff but I would probably pass if it was my monitor. Definitely not doable by a typical user. (Assumes you did the connection_s_ checking as recommended by handy.)
Also try different (lower) refresh rates for the given resolution.
If something in the FAQ helps, be sure to post a thanks to Sam in sci.electronics.repair. He’ll appreciate it.
I forgot to mention that this is my computer at work. I’ll let the IT department know. (Not that anything will get done, mind you!)
First of all no tech in the world is going to advise you without knowing who made the monitor & what year it is, which we don’t know, of course, plus, I thought it was a personal monitor but hey, you can get your company to do it for ya.