Users of Spell Catcher X should be aware that the new Safari 3.0 beta has a bug that screws up Spell Catcher auto-completion in a number of Apple apps, notably Mail. Instead of substituting the text for your abbreviation it will keep the first letter of the abbreviation and add the full text after it (various other oddities have also been reported). The bug is in the version of WebKit that the Safari beta uses and can’t be worked around, in most cases anyway.

More information at http://www.rainmakerinc.com/forums/index.php?showtopic=1357.