Question [solved] Emergency, my website is screwed

I just don't believe this. I have been testing the upgrade on various websites and everything has gone just fine. As soon as I do on my major site, everything goes wrong. The site will not even show, it's just a blank white page. Please, can someone help

www.oscarfishlover.com/

Check your PM.

One thing I didn't try was switching templates, I bet it's got something to do with that?

Just a thought, I didn't disable any old plug-ins or modules, could this be the problem? I don't want to go on the site in case you are on there at the same time.

YES! This can be the main factor of why your not seeing anything on the front end.

What template are you using?

Also try going down the module/plugin list and disable and see if you can breathe life back into your site.

The template I am using is okay because I have a couple of other websites using it and I have tested the upgrade on them with no problems. However, I absolutely know for sure that there must be an old plug-in somewhere on the website because I developed it with 1.0. Oliver is giving me some help and I don't want to go into administration using the same login details in case it causes a conflict. So I'm sitting here chewing my fingernails down to the bone.