Ok, so this was weird and took a while to track down. After setting some styles for a TabControl, a 1 pixel gap appeared between the tabs in the header of the control and the tab body:



Firefox had no issue as usual. After the traditional flurry of setting margins and padding to 0 on every block level element in existence, I was beginning to tear my hair out. Fortunately I had another site that had a similarly styled TabControl that didn't have this issue and by process of elimination I found the offending tag.

To my surprise it all came down to the particular font I had chosen! I changed the font-family style for my body tag from 'Verdana' to 'Arial' and everything was fine! After a bit more investigation I found that it only happened when using 'Verdana' for certain units of the font-size style - If I was using 'pt' units the issue appeared but it was fixed by changing to 'px' units. This way I could continue using Verdana. Has anyone else seen something like this before?

Jimmy