[drupal-support] access denied while logged with uid = 1

[Maykel Moya]

I have a drupal 4.6 serving multiple sites. Some random problems are
arising eventually.

1. php out of memory. i allway had 8m for php execution, now sometimes
php cries, is this normal.

2. sometime I get access denied even while logged as admin (uid = 1).
For example, I can list the access control table /admin/access, but if i
change something and save permissions, i got an access denied. Then,
while the path is still /admin/access i can't relogin, i should manually
point the url to / and the login.

Any advise/workaround for at least manage access control is welcome.

Regards,
maykel