Thanks for the info clickbuster. What was throwing me was that I use IE and it showed fine, pics add up to 720, table set at 750, text in a cell than spanned 2 pic cells, which here looked OK, as I say.
I was trying to get the most out of my thumbs without going over, hence the 4 x 180, think I'll keeep it at 4 x 170 next time I use that template to be on the safe side, and as Cleo said, nest a single table with width set inside the double text cell.
Not to mention keeping that code you supplied in the body tag
You live and learn....