Stuck in a redirect loop

Hi.

I’m an amateur trying to run my own site. Apologies in advance for my ignorance.

The difference between the rest of the site and the login page was too great so I installed MTL. I read the manual and created what I thought was the appropriate slug, and since then have been in a redirect loop. The only way I can logon is via the hosting provider.

Before asking for help I’ve attempted to fix it myself. This is what I’ve tried:
– installing TML Redirection;
– installing TML MS Fix Master, but I must be doing something wrong because as soon as I activate it it disappears from Installed Plugins (the folder is still in wp-content/plugins);
– searching these forums;
– searching the web for all spellings of the problem I could think of;
but nothing has made any difference.

Before writing this message:
– I read the Troubleshooting sticky and edited wp-config.php so that errors are logged but despite forcing the loop dozens of times no debug.log is created anywhere on the server;
– I installed Debug Bar and it shows thousands of items but none contain My Theme Login, MTL, login, logon, wp-admin or any related words I can think of.

My hosting provider runs Linux Fedora and Apache 20120211. WordPress, theme and plugins are all up-to-date.

I’m very sorry I’m so ineffective. Can someone suggest something I can try?

Many thanks in advance.

D.

The page I need help with: [log in to see the link]