I've been having an issue for a couple of days where a topic flagged as "new" will do this when you open it up:

This only occurs for the first post in a topic. Any subsequent posts are formatted correctly, even if the New graphic is present.
I'm running Safari 5.0.5 on a Mac (OS 10.6.8). I first noticed the issue a couple of days ago, specifically right after updating to Safari 5.1. I've subsequently reverted to 5.0.5 but the issue's still there; it's possible that bits of 5.1 are still on my system though!
Has anyone else run into this?