Just checked serps this morning and this site is back to number 2!
I changed the header tags on a few pages, but never got around to fixing them all up, so really have nfi what happened. There was nothing dodgy on the site to get it penalised in the first place. Some people earlier in the thread mentioned it may take a month to come back, looks like that was right. Thats good to know, I won't freak out next time a site drops off for no reason for a couple of weeks.
I changed the header tags on a few pages, but never got around to fixing them all up, so really have nfi what happened. There was nothing dodgy on the site to get it penalised in the first place. Some people earlier in the thread mentioned it may take a month to come back, looks like that was right. Thats good to know, I won't freak out next time a site drops off for no reason for a couple of weeks.