OH YES...
Highly unfortunate. I live in California and they never seem to completely go away. Part of the problem is that they love to live in the semi-dirty bottles that I keep for refilling. If I had more space, I'd be smart enough to put the bottles elsewhere.
The other problem is the blow-off tube. I am never short on vigorous, foamy primary fermentation. Gnats love standing water. Standing water plus nice sugary wort, fuggedaboutit.
I have to dump my airlocks periodically because I hate to see gnats drowned in the vodka. At least they died drunk as hell.
I'm sorry this post wasn't more helpful, but I commiserate.