I have reviewed the forum posts where the same error has been reported, but none of the situations, and none of the solutions apply. The error:
Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 1966080 bytes) in /home/username/public_html/wp-content/plugins/gravityforms/form_detail.php on line 2177
Unlike others posting this problem, the error in my situation did not happen during installation, etc. It happened when I tried adding a form. I tried this several times.
I upped the memory_limit to 256M, tried deactivating other plugins, and updated the GF plugin using the auto-update. None of these possible solutions is working. I can use everything else in WordPress (only since updating GF), I can access GF Settings, etc, but I cannot get to Forms > New Form. When I try to add a form, I get the "Allowed memory size" error.
WordPress 3.3.1
GF Version 1.6.3.1
PHP 5.2.17
MySQL version 5.0.92-community-log
Apache version 2.2.21
OS Linux
Memory limit (256M, verified with phpinfo.php)