'Manage fields' causes the memory to get exhausted

CCK is the only third party module installed.

I also tried raising the PHP memory limit to 256 MB, but the only result obtained is that now the error message is changed to:

PHP Fatal error:  Allowed memory size of 268435456 bytes exhausted (tried to allocate 1440 bytes) in /Applications/MAMP/htdocs/dr7/includes/common.inc on line 74.

The same error message is shown if I change the memory limit to 128 MB.

I tried it, but it didn't resolve anything.
Looking at the difference between the last committed code (1.6) and the previous commit, I don't see much changes (except in a debug function that is not called in the menu callback used for the page which gives me problems).

Did you mean another version of cck.module?

I found it.
Now I can see the content type fields, but I get other errors when I click on the Display fields tab; fortunately, this time I don't get a WSOD.

The error messages I get when I click on Display fields are the following:

Notice: Undefined variable: type in cck_display_overview_form() (line 589 of /Applications/MAMP/htdocs/dr7/sites/all/modules/cck/includes/cck.admin.inc).
Notice: Undefined variable: type in cck_display_overview_form() (line 590 of /Applications/MAMP/htdocs/dr7/sites/all/modules/cck/includes/cck.admin.inc).

This happens for the content types that have a CCK field, and for those that don't have any CCK fields.
Actually I can only report the error for the content types defined from Drupal core modules.