To despair: iTunes won't update a bunch of apps

Okay, since I am testing a lot of apps I have 2,000+ of them on my MBP (10.6.5). I did not update them for two weeks and now there are 124 updates ready. But iTunes won't let me update them since two days. There is always an error message: "Try it again in some time." Other tasks (downloading apps) are working fine. Will that ever change?

What can I do? Should I call Apple support?



Thanks in advance for any hints.

^ No, only one account.

In the meantime it worked. But it was a pain and needed three hours, full of error messages.