No I can switch to offline. What I'm saying is if I'm online, and say im away from my computer, and the internet goes out, I can't switch to offline anymore, I have to wait until Steam goes back online before I can switch to offline... unless they changed it.I had that issue too, but then realized that the reason Steam wouldn't go into offline mode was because it THOUGHT I still had internet access, and was trying to synch some saves before going offline. The obvious problem being that I didn't have internet access.
In my case, it was the virtual adapter for Hamachi, which lies about it's status and was reporting an internet connection even if there wasn't one. Removed Hamachi, Steam was no longer lied to, offline switching has worked just fine for me for months.