Help with Fatal error: memory exhausted - elgglib.php


All at a sudden I get the infamous White page when connecting to my own test Elgg installation which I've been running for 21 months with no problem.

I activated display errors in .htaccess and I get the following:

Fatal error: Allowed memory size of 262144 bytes exhausted (tried to allocate 19456 bytes) in elgg/engine/lib/elgglib.php on line 405

Other times I get the same but with line 525

My .htaccess file says that the memory limit is 64M - so I don't understand.
I've also tried with the 'disabled' file placed in /mod but no success

Any clue what could be wrong?