OK, there was a Problem with Table-Prefixes not being supported properly - this explains the SQL Error.

Open config.php and place
there.

Then go to Plugin Manager and delete all Plugins from this Hack.
Afterwards please check (in phpMyAdmin) if you have a row for grouptitle = 'memberlist' in Table vb3_settinggroup.

any particular place to put that code?

Nevermind. Figured it out. Just stuck it anywhere and was able to get back in.

And yes I do have that row.

I think I found the Problem - stupid typo ;)

As said, delete all Plugins from the Hack, then remove the define from config.php, redownload and it should work then.
Sorry for the mess.
(I should start using Table-Prefixes on my Testserver ...)

Okay, will try again. Thanks Kirby!

Worked this time! :D

Hate to be a pain...but the settings for the usergroups aren't sticking. When I change them...I get this error at the top of the page:

Warning: mysql_real_escape_string() expects parameter 1 to be string, array given in /includes/class_core.php on line 598

Hmm ... where exactly do you get this error?

OK...when I went to usergroups manager and selected the usergroup I wanted to edit...then I changed the settings (all to yes)..hit submit...and on the redirect screen (at the very top) was that error. I had to act quickly to copy it then redirects to the main usergroup manager page. When I went back into the usergroup that I had just edited...the settings that I had changed did not stick. Hope this makes sense.

And it does only appear in Usergroup Manager after hitting Save?