Magento

When i edit a product or create a new one as soon as i upload an image i get a blank page in the front end. even if i switch themes. How can i fix this any ideas??

This is killing me i really need help on this one i can create products but if i add an image the page goes blank.. If i modify one of the dummy products that came with the isntall same thing. As soon as i modify the image the page goes blank and if i delete the image then i can see the product page fine. I tought the problem might of been the flash uploader but i changed it to a regular uploader and i still get the same result :(((