Yeah, intermittently. I think it's just the Sunday Blahs (heavy traffic both here and eBay).
Even though I never manage to get it done, it's often a good idea to schedule any listings for Sunday a day early.
I've been getting the standard error message and the occasional runtime error but it seems if I just wait a bit it'll go away for a while.
I've also had luck a couple of times by saving the listing I'm working on. I got the error message but then went into Saved Listings and it was there and then I could work on it okay. Could be coincidence, but who knows.