If you are having problems logging into the site from your phone it could be due to a couple of things.
1. You have to have cookies enabled.
2. Could be a cache thing so if after you enabled cookies, and you still have the problem, then clear phone's browser cache.
This could be also happening with some tablets/ipads as our system is safari compatible.
So if you do the above two steps with your phone and tablets and you still can't login, be sure to post here.