problem with downloading

Hey, I've got a little problem with my cs.
When i connect to server with a map I don't have, a message shows that i don't have that map, bkz_goldbhop.bsp for example. At first I thought that it's because the command cl_allowdownload 0 but it was set to 1 when I checked it. I don't really know what to do and it's very annoying when I can't join servers.
Any ideas?