Originally posted by: TheSpaceman
You can stop Flash content running by disabling the relevant the ActiveX controls setting (can't remember which one after using Firefox for so long, but trial and error will do it) for the relevant security zone. Note that this will also stop any other ActiveX controls from running as well, but aside perhaps from PDF files, you'll not be missing much.
You will probably also have an option for Prompt which will really irritate the hell out of you by having to click No repeatedly as a page loads!