There seem to be ongoing issues with Safari... but just in case this isn't *only* limited to Safari I wanted to bring it up.
I'm using the latest build of 1.5 (Feb 14) and when I tried to put a
<!--more--> tag within an open <OL> (but not a list), Safaris' CSS rendering of the page freaked out. There were sidebars and blogrolls everywhere!
(Actually, they were just "shifted over" about 100px)
It seemed to still be fine in Firefox (on Mac), so this might only be a Safari issue.
Here's the post I had the "more" on...
Had it between the 1st and 2nd item.