My server was full at 20/20 when I switched to plaza_b6. About 11-12 were left after. I think 5 or 6 of those that left got that problem. A couple of the players that complained to me about were able to connect after crashing twice. I don't really have custom content on the server other than the suicide bomb... and I run ULX admin mod, if that helps.
Shifty, much thanks on this great map. I tried it on my server last night, but I had a problem with it. While some players were downloading it, they crashed with an "Bad Inline Model" and I lost almost half the players. Do you know what this is? I unfortunately can't use it until this is fixed... and this is the only map I have this problem with.