Just a self note here.

Been working on a Magento project, and everything was going smooth until when it was time to install some useful Extensions.

I ran across after installing through the Magento Connect Manager , Everything installed fine, no errors, but when I went into configuration, and trying to configure the Extension. I get 404, PAGE NOT FOUND error.

Woah, I tried reinstalling Magento ground up thinking maybe it was something I missed in the new installation,  and it was still same outcome.  Than I tried using PHP5.3 (was running on 5.2 without realizing it)… outcome?  still same 404 Page not found message when I try to configure.

The SOLUTION?!

LOG OUT of the entire ADMIN page, and log back in.   It seems like there’s admin access info that needs to get updated by logging out than back in.  This fixes the problem!!!!

I spent the entire day trying to see what was going on, because there was NO WAY that all extensions aren’t compatible.

Well if anyone runs across the same thing, there it is.

Perhaps I missed something in the documentation, but this was some stupid run around.. HAHA!  no harm done.