asquithea - 7:30 pm on Jun 8, 2004 (gmt 0)

I know of a solution for Firefox, at least:

Go to about:config and change the browser.xul.error_pages.enabled setting to true. This will suppress the dialog, but you'll find that the failed URL is lost from the address bar. Fix that problem with the ShowFailedURL [texturizer.net] extension.