I don't know if anyone else has been bothered by this, or has even seen it happen, but I was sick of having my windows in OmniWeb cascade every time I opened a new browser window. If you wish to disable window cascading in OmniWeb, simply open up the terminal and enter:
% defaults write com.omnigroup.OmniWeb[Enter this on one line, with a space before the "OAWindowCasc..." bit].
OAWindowCascadeDisabled -bool YES
Mac OS X Hints
http://hints.macworld.com/article.php?story=20021121061124758