incoming email, can't select what to assign it to

[ElgertS]

I am running 4.5.0f and am now finding that I can't associate incoming emails with opportunities or anything else for that matter. I can use the create button to make a new one, but can no longer select an existing one.

Mac OS X Server 10.4.8
PHP 5.2
MySQL 5.0.27
Apache 1.3.33
Firefox 2.0

Also, it would be great if the quick create had opportunity as an option.