Today, I experienced the same issue, It is the form authentication data, IE is appending it to the URL instead of using cookies, even if the cookies are enabled. I don't know why only IE is doing this, may be due to some settings in the IIS, which we need to configure.
Any way, I fixed this by adding
cookieless="UseCookies"
property to the Form tag in Web config, below is the authentication section from my web config
<authentication mode="Forms">
<forms loginUrl="~/Account/Login.aspx" timeout="2880" cookieless="UseCookies" />
</authentication>
<authorization>
Hope this will help you