I had an older couple at one of my tables tonight. I took their drink order, and then their dinner order. Before they got their dinner, I walked by a couple of times to check their drink levels, but didn't stop or interrupt. Another server delivered their food while I was taking an order; I went up to ask how their dinner was. The wife said hers was fine; the husband said he hadn't tried his yet. I asked if they'd like anything else and went on my way.
A few minutes later, I figured I'd better check on them again in case anything was wrong with the guy's food. And he totally bit my head off! "Are you back again? Can't you stop bugging me? Everything is fine, okay? JUST FINE."
In nine years I've never had anybody get pissed because I was there too often! I just said "Okay, then I won't come back until your plate is empty." and smiled. I think after that his wife scolded him, though, because when he was completely finished and I asked if they wanted dessert he was very nice and kept saying things were great, I did great, etc. etc.
But seriously--who complains that a server is giving them too much attention? Especially because she's checked on you twice? Crazy fuckers.