thanks for your help.
I also thought that a table of my db got messed up or deleted - so i reverted to a backup and then an even older backup. Problem persists. I know that the problem wasn't there in the backup as i ran a test buy previously and everything was fine.
In regard to the backup bit: I was wanting to upgrade my store but i was worried that the one click upgrade would ruin the shop - so to test on a dev version: i created a subdomain on another .com domain i had - uploaded all the files via ftp. I then manually did a find replace (notepad++) on a sql backup of my main the store (to the point it to the subdomain url) and uploaded the sql backup to the dev site. I did the upgrade on teh dev site and everything seemed to work. Then this problem with the main site.
My thought was that there was something in the dev site that i upgraded that was still pointing to the main site? Im too much of a noob to know