Well, thank goodness. I was about to give up all together. I mean... not that I'm happy its happening to you... but it sure is better that its a Bnet problem than a map problem.... I couldn't see anything wrong. 0.o
This problem has plagued my map hard. It lags really bad now after the patch, and drops players after about 2 min.
It is only affecting some maps.
I don't know if I should spend time and try to figure out what is different in my map that is causing this and try to fix it, or just wait it out. My map (Overrun!!) doesn't lag at all when I play it solo in the editor, only online.
Although this solution may reduce the likelihood of drops and lag, the problem is not specific to custom maps. There is a thread on the sc2 beta bug report forum where a blue has requested the player id and time of games where they were dropped, which include custom and normal games.