I don't have L/R scroll issues, I'm at 1024 x 768 on a loaner computer, no problems loggin in either. Try clearing your cookies, it's still might be seeing the old BB and using it's prefrences in your browser.
i only have log in issues when i clear my history and stuff. after i get logged in the first time, i don't have any problems. i haven't had any with the scrolling either, and i've used computers with 1024 and 1152 res.