On 2 sites I'm working on (with XOOPS 2.3.1) I have the same problem. It happens only when I try to log in as a user with wrong user name or/and password, I'll find me in a loop which will time out after a while. There is no problem for a real user or the administrator.

Just before the loop i see:
Incorrect Login!
using XOOPS authentication method
If the page does not automatically reload, please click here

And while the loop (page is refreshing about once a second):
Sorry, you don't have the permission to access this area.
If the page does not automatically reload, please click here

And after time out:
Request-URI Too Large
The requested URL's length exceeds the capacity limit for this server.

I found out by myself that it is, if I don't give module access rights to the Anonymous Users Group for the module User Profile.
I don't know if it is by design, if it is a bug or a problem with my serverconf.
Also, if I don't give module access rights to the Registered Users Group for the same module I cannot log out.

I beg your pardon, it's 755 but recursive, so all FILES are set executable! I think this is unnecessary with PHP (i may be wrong, but i don't have any file executable in my web space).

File Permissions have to be set more secure than this.

Greetings

To make sure, i have re-downloaded (with wget) xoops-2.3.1.tar.gz from sourceforge.net/project/showfiles.php?group_id=41586&package_id=153583&release_id=632372 to verify another time, but it's the same. All the directories and sub-directories with all the files in them are set to 777!

Can someone verify this.

greetings