Hello!
I make this post so that you can get online and check your auctions.
1 hour ago I logged on to check my RMAH and see if I had sold a 40+ euro neck. What I saw when I logged on was that the item was missing.
I check through all characters, checked through all the tabs on the stash, but it was nowhere to be found.
I checked the forums and there is already a 26 page thread full of people complaining about missing items, euros and gold.
Seems like the same issue happened yesterday, hopefully it gets resolved soon.
edit: It seems like the thread I was looking for has disappeard, but here is two other ones.
Auction House Issues - UPDATED 3/7/2012 - Forums - Diablo III
http://eu.battle.net/d3/en/forum/topic/4848026129
Thread from yesterday:
http://eu.battle.net/d3/en/forum/topic/4848905898