Got Norton support via phone and he did a clean removal and reinstall of 2012. Seems to work better now. Scroll problem happens when the NIS select line is at the top. Work around is to click it off, the scroll is ok. He says the problem is at the user site. Identity safe is loading id and pw for most sites now. But some like etrade logon load "userid" instead of my user name and password ok. Deleted the entry and saved a new login, but problem remains. Guessing the etrade page is causing the problem. Anyway, working much better now. I may try support again if I can zero in on the problems.
Norton customer services told me that too, that the problem was with the web pages and not NIS12. If the problem is at the user site then there are an awful lot of sites that don't work with Norton IS. Also this doesn't happen on the same sites in Google Chrome!! This problem seems to be related to Internet Explorer 9. Doesn't happen with IE8 either, I've uninstalled IE9 and gone back to IE8 and checked. Also I find that often the Identity safe will auto fill a web page login sometimes but not others. Same page, same login but different times. It always worked fine in NIS11.
If anyone has any answers I'd be grateful because I find identity safe really useful and it was my main reason for staying with Norton but given this annoying problem then I have no reason to continue using it.