STILL cant login to AdminCP!!!

[Tschia]

Mayday-Mayday:
I've read in several other topics also about this 'feature' of vBulletin: after been using it for months, now suddenly I cant login to my AdminCP anymore.
I get the welknown 'Thank you for logging in.../ Click here if you dont get redirected automatically' and then I'm forwarded to the AdminCP-login-screen once again!

I've already tried the underneath suggestions, without any luck:
1-Edited the 'includes/config.php' by adding another userid as a SuperAdministrator
2-Reset the cookie domain and path with 'tools.php' (from the 'do_not_upload' folder)
3-tried the 'mycookies.php', which als resets the cookies or so, from another tread
4-and even re-uploaded (not re-installed!) the original vBulletin files (after having backed up, just in case)

What else is there to try?
I know it's not my local cookies, since it's also the case on another PC. I'm using vBulletin version 3.5.4 and I'm out of options...

Any other help is welcome...

Thanks in advance!

[Scott MacVicar]

Can you open a support ticket with your board url and admin details, i'll check the header details for cookie errors.

[Tschia]

Thanks for the fast reply...

I've created a with a reference to this thread...