Well with a lot of help from chavo we pinned the problem down.Well with a lot of help from chavo we pinned the problem down. Turns out there is a bug in IE that doesn't allocate enough memory when you use javscript to store the cursor position of a textarea (which is exactly what I was doing). chavo also sent a fix but as there is more than one textarea on the page it doesn't work so to the stop the crashes I'll just stop storing the carat position. The upshot of this is shortcut tags wont be added at the cursor position but at the end of the text, but it's a small price to pay for typing in a long news article and having IE crash when you click the preview button. More information for those that are interested is here -> http://www.faqts.com/knowledge_base/view.phtml/aid/11608/fid/130. Thanks a lot chavo for your time on this. A fixed newspost.php is available here.