Error: Attempted security breach. Please re-login

Hello everybody,

my first posting in this forum. I searched the forum and elsewhere but could not find an answer. If I missed something please push me in the right direction.

I run Gallery 1.5-cvs-b242 embedded in Mambo 4.5.1b. Gallery and album directories are outsite of Mambo. Everything works really great but some of my visitors complain about getting this Error: "Attempted security breach. Please re-login."
When this happens they are no longer in Mambo but on a native gallery page showing this message and a login form. Since they are not registered, login is not possible. To see the gallery again they have to wait for some time.
Most but not all of those having this error use AOL. No idea if this is part of the problem.

I'm a beginner and might be wrong, but as I understand the error is caused by some kind of hacking protection and seems to be related to session handling. When the visitor accesses the gallery a session ID that is checked for every operation. If something changes I will get this error.
But what can change on visitor side to cause that error? Maybe new IP address after timeout of dial-in connection? Btw. can you tell me who or what determines the session lifetime?

I hope somebody can tell me how to avoid this problem.

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apache 1.3.20
php 4.3.3
gallery 1.5-cvs-b242
ImageMagic 5.5.7
OS Linux

Thanks for your answer.

Problem seems to be solved now after I updated to latest cvs version (build 338). Now my visitors from AOL are happy again . I saw in the changelog that the function causing the trouble is disabled since b321. Could have checked that before, sorry.