there are temporary db files written to the disk when editing anything in the forums. It might be possible that one is writing sht in the one forum so the db for the second forum cannot be opened for the second one as your space limit exceed right that moment.
Looking for german Snitz forum? Suchst Du ein deutsches Snitz Forum? Hier findest Du eins...
It doesn't matter what you have. The server stores things such as transactions on a temporary cache file. When that is full, I think it's supposed to automatically overwrite old ones but sometimes it doesn't. Again, you would have better luck contacting your host.
the forum i'm trying to edit is the bigest forum from all the others. (more the 230,000 messages) and it's the only one i can't edit. it can't be space problem since i can edit the other forums but not this one.
yigal7, why don't you believe what others have been telling you. This is a problem with the server. The only way you are going to resolve the issue is to contact your host.
Is this not getting through to you? What in the world would make you think that the forum is a piece of hardware? The problem is stated blatently in the error message. It's the problem on the server, not the forum software. Just think about it. If I were you, I'd switch hosts. The host will of course blame the forum software, no host wants to admit that they use crap for their servers or not allocate enough memory for the temp disk space.