Generally speaking, cases where IE users can't log in or hit a redirect loop have been traced to either browser-specific problems (eg., their security settings prohibit them from logging in; or they have some sort of add-on that's interfering), or server-specific problems (eg. problems with proxy setups, URL rewriting, etc., although this will usually affect more than just IE). I'm not currently aware of an OJS-specific IE login problem. With enough actual issue information (problem URL, and OJS/OCS/PHP version informaiton; IE version information; security settings info; and so on) we can always take a look and see if we can replicate; but getting this information from users with this problem has been difficult historically, for what reason I have no idea. Debug information is appreciated if you have it.