I have a very strong work ethic, so it's not work ethic, per se, that's been problematic. Constant lateness, volatility, inappropriate behavior, not getting along with people? Yeah, those have happened.
God knows I didn't rack up 39 jobs for no reason (though it's been way, WAY more often a case of me quitting).

But there is one saving grace. One (apparent) rarity: I don't goof off. At ALL. No standing around chit-chatting, phone checking etc. (Hey, there it is: work ethic!)
I don't talk. And if I'm hypo and running motormouth, I don't look up, I don't pause (What? As IF I can't do everything at once! Lol.) Getting a LOT done can "cover a lot of sins" as they say. "Sins" being all the above stuff, plus the inconsistency depressive sludge brings to the picture.

(It is important to note that I've really only ever had super-basic hands-on work. Anything requiring complex thought or social navigation, forget about it. I couldn't look at charts, sit through meetings, etc. Or manage people. That one's positively laughable. )

Alas, between mental and physical issues, I can't do even that enough anymore to get by (and it kills me to have to admit it). But it's my traditional MO.

Bluebicycle, I agree -- if you're getting the work done, it shouldn't matter.

(BigMike, Yes! I hate the term "high functioning" too. It can be very misleading.)