strange new problem with IE

Hi, For about the past week or so (after getting a new IE update) I've been having strange problems with IE and my PHP scripts. One out of ten times or so, when you click on a link or open a page, IE pops up a file download dialogue instead of displaying the page. It's asking you to open or save the page you are trying to visit. This is on a site that's been working fine for about 6 months. It seems to happen on any type of page, whether it's just grabbing DB content for display, or has a form and is updating a database. Anyone else seeing this? Any thing I can do? Sam