There's a small bug in the 4.1 release if you are using LibTidy (look in Settings, under "Feeds"). This is only an issue for users on Windows and Linux x86 - we don't ship the library on other platforms. In any case, with the 4.1 release, we added a fix for the spacing issue - links were getting drawn without spaces between them and the following text. However, the fix for that unintentionally screwed up <pre> tags - a problem if you are viewing source code in a post.

If that's something you see happening, you can do one of two things: either turn LibTidy off, or use the update tool to grab the new revision of the library. It will load without needing a restart.