I have a GFC wall outlet in the garage. I put up a new florescent shop light and plugged it into the outlet. It works fine for maybe an hour but then kicks the GFC breaker off. Sometimes it will kick off the breaker as soon as I plug it in. I have plugged the shop light into other outlets and it stays on and works fine. The GFC outlet could be 20 years old. Is my outlet bad or do florescent lights not work well with GFC outlets?
I would swap the GFCI with another one, and see if the problem repeats. Then replace either the light or GFCI, accordingly.
No fluorescent fixture should ever trip a GFCI, if it does, it's the ballast, either due to being really cheap, or having a fault. Given that ALL garage outlets must now be GFCI, I can't see how anyone could get away with selling a fluorescent fixture that trips GFCIs.
Like Machavity says, replacing an old one isn't a bad idea. And the best reason is the march of technology: New ones are better. Just don't lose that advantage by getting a bottom-shelf junk unit.