The overlap thing happens a lot in IE too;mostly on blogs...
...but also on many magazine-type sites (like Wired and CNet, IIRC). Could well be that it's that "crappy CSS support" cited earlier -- but then I think it happens in Firefox too, on some of those sites.
The alternative is that sometimes, you get the left-margin thingies on the left, the right-margin thingies on the right; and the center column, that wouldn't fit in the middle, only begins below where the left and right columns both end.
Dunno whether it's table columns or column "div" elements that are specified in percentages that don't add up to 100; probably some of both. Sucks, either way.
Maybe browsers should stop assuming that Web "designers" know how to add up to a round hundred, and start using whatever the sum of these morons' "percents" add up to as the total.
