"Invalid response from server" while running a batch operation

Hi

I have noticed that the "Invalid response from server" message comes, when a batch operation is working.

More Details:
Logged in with 2 Browser and differrent accounts. One browser is logged in as moderator and the other is logged in as user.

1. I posted some articles as user.
2. Updating some workflow states (same content type), workflow states are updated via batch operations
3. The batch process ist working, and I want to post a new article as user. HS does anything, just the message "Invalid response from server". I must wait of the end of the batch process and then load node/add/article new. Now it works.

The log messages are the same, as mentioned here a lot of times before.

The bug is reproducable on my site.