Might as well add my experience to this. I regularly open 120 Super Packs (40 of each) and process them to the AH in 30-45 mins. For the past 2-3 weeks, after I get the 1st batch of enhancements out of the mail and into the AH, when I go back to the mail, I cant claim anything. It continually gives me the message "Character or Account item claim failed, another request is pending". Sometimes this lasts 5 mins, sometimes over an hour. Ive logged out, switched characters, logged into another acct then back to this acct, zoned (bases, common maps, regular maps) went in mish's, claimed/sold things on AH, everything I could think of.
Prior to this, I did the same exact thing for the past 6 months and never had an issue.