Restoring a screwed up EE 1.6.9 exp_site table

I made a stupid mistake today of editing a path in the exp_site table on one of my sites as I had a problem updating in the admin panel.

Since doing that my site has gone down and from investigating it seems that the data stored in the table wasn’t serialised properly and so the site is just not working. I’ve scraped the forums and can’t find an answer on how to fix this.

I do have a back up from yesterday that I tried to replace both the whole database and just that one exp_site table and both throw up the error “Site Error: Unable to Load Site Preferences; Invalid Preference Data”

I’m not sure how to fix this and wondered if anyone has come across this problem before?