Memory-problems after a failed upgrade to 3.2.1

Hi,

I have a problem now which many had, but I still can’t solve it. After a failed upgrade to 3.2.1 I get the following error message:

Fatal error: Allowed memory size of 262144 bytes exhausted (tried to allocate 19456 bytes) in /home/stgoed/public_html/wp-includes/default-constants.php on line 128

I already made the adjustments as can be found here(adjustend to 64M), but that didn’t solve the problem: http://codex.wordpress.org/Editing_wp-config.php#Increasing_memory_allocated_to_PHP
I already disabled the plugins in the database but that didn’t change the situation.

Strange thing as well is that according to the PHPinfo-script, the memory-limit is on 48M, which is different then the 256Kb which is mentioned in the error-message.

Anyone has a suggestion on how to solve this? Thanks!