Checked the database, saw it was weird (possibly corrupted) so I figured I'd delete it, make a new one.
Don't know what you mean by weird, but if you use CPanel, you can repair a database instead of deleting it.
On a totally fresh install, I put in 'admin' and 'poll' as my password and I can't log in!
Advanced Poll 2.0.7 db allows you to enter your own username and password upon successful installation. You get a screen asking for it. So, why would you use something as generic as "admin" and "poll" for your username and password? Perhaps you missed this in the installation.
Anyway, I used a test site to see if I could change the admin password from the database. Everything went wrong and as you said, I could no longer access admin, so I guess I had better make sure I only change the password by using the "Change Password" feature in Admin, as is no doubt how it was meant to be.
I was only able to get back into admin by deleting all of the poll tables from the database and running install.php again.