If you are hosted by us, I would certainly submit a ticket, especially if you can reproduce it.

Wait, now that I'm thinking about it.....you are saying that you, for example, go into the skin section, and work there for like 30 minutes or something, hit save, and you have been timed out?
Ahhh....that makes more sense. I was thinking, going into the skin section, edit, hit save, and the connection to the server timed out. That's different, I get what you mean now. See, this is really a security point more so than anything else. A good idea for you (especially with CSS, I do this myself just because it's easier) might be to copy/paste the contents to a notepad document, then do the edits, then copy and paste them back into the ACP. If it times out, you still have them in the notepad document and can just login and do it again.