[Typo3] BE tree frame problem

[Chris Paige]

>> The onset of this problem was sudden. I guess this means that my firewall 
>> settings were changed recently?  The problem persisted when I turned off 
>> my Windows XP firewall.  So the conflict must occur in a network 
>> firewall?  Is this a correct understanding of what happened?
>
> yep. maybe caused by auto update of Checkpoints Smart Defense!?

Actually, it works fine (without the patch) on a second installation of 
Typo3 on another server.  If the problem is simply a conflict with the 
network firewall or my computer firewall, then the second installation 
should have the same problem.

Still the patch did resolve most of the trouble in my first installation. 
Is there some other factor based in the server that could be causing the 
conflict?  Would the server itself have some sort of firewall?