My application's cookies work in all browsers EXCEPT IE! ARGH!

Hi everybody,
my web app www.papastraindepot.com is relying on cookies for shopping cart items and a remember me function. I set an expiration of 90 days on all of these cookies, and they all work in the browsers I've tested on (Safari, Chrome, Opera, FF) BUT -- in internet explorer, the cookies work, but do not keep the expiration that I apply to them. When I look in the developer's tools and view the cookie information, ALL the cookies say expires at the end of the session!! Kind of useless for a 'remember me' function.

Does anyone have any thoughts?

I'm writing them in a pretty standard way

Response.Cookies("PTDcart").Item("Items") = "0"
Response.Cookies("PTDcart").Item("Total") = "0.0"
Response.Cookies("PTDcart").Expires = DateTime.Now.AddDays(90)
Response.Cookies("PTDcart").HttpOnly = False

I've been 'googling' this for 2 days and haven't found any answers

thanks,

Larry