Admin Login Trouble

I cannot login to my wordpress blog.

I have tried every single trick for password reset listed in the Codex, here and here.

I even reinstalled my entire wordpress version, and upgraded to 3.0.1. The problem, however, has existed for a long time (before the upgrade). Before I upgraded, I was using 2.9.1.

At some point in my troubleshooting, I was able to get the site to send me the automatic password change email, which it wasn’t doing before. However, when I use it, I get the message “Sorry, that key does not appear to be valid.”

There is only one user on this site. The name is “admin” and the ID is “1”.

[EDIT, ADDED PARAGRAPH:] One possible problem, is that I do not seem to have an .htaccess file. (I am using FileZilla, and have it set to force show hidden files.) When I try adding one and pasting in what Google searches tell me should be the default code for an .htaccess file, my website stops working, generating a 500 Internal Server error. (I won’t be able to edit httpdconf or anything, because I am not hosting the site myself.) I don’t know if this is the problem, but maybe it will be a red flag for somebody.

My website is https://students.brown.edu/Brown_Democrats. It is case sensitive, as set by Brown University hosting, (NOT ME! =] ).

The URL used to be https://brown.edu/Students/Brown_Democrats, but Brown changed the server over to the current format last Spring. I believe the issue may have originated then. However, in my phpMyAdmin database, under wp-options, both the siteurl and home are set to the updated url, so I’m not sure where the problem could be. [EDIT, ADDED SENTENCE:] Under Brown’s hosting, everything must be sftp, not ftp, which could be making a difference.

I am using Mac OSX 10.6.4. I primarily use google chrome, but have also been trying Firefox and Safari, and clearing my browser cookies periodically in all of them, with no luck.

If anybody has any idea what the problem could be, your help would be greatly appreciated.