IE6 Internet Explorer 6 Blank Pages

When I use IE 6 the site comes up with blank pages in certain area.
For example, when I add something to my shopping cart, the page goes blank.
No error.
If I go back and click on Login, the item appear in the shopping cart side box.
When I click on the shopping cart link, I can see the item in my shopping cart.
When I click on Checkout, I get a blank page again. No way to continue from there.

Any ideas? Could it be a file permissions issue?

And now it also happens in IE 7 and FF. CRAP!

Troubleshooting blank pages: https://www.zen-cart.com/tutorials/index.php?article=82 (esp step 2a)

Thanks...that helped.
Lead me to find a hard return at the top of my index.php file.
Apparently that is the cause of the blank pages. I know this because when I take it out, problem solved. When I put it back in...problem occurs.

Fricken weird.