Use forum search please. Here is the same thread, even it's name is identical!
Unfortunately, there is no solutions posted in that thread, other than a suggestion to not use session beans, which is hardly practical.
I had the same problem on page referesh, and it got solved when i searched view source( in case no error was coming) for this id and then assigned all the components which did not has explicit ids, some ids.
This included a4jsupport and a4jregion etc.