Well, it finally worked for me last night: this is an improvement. (the new "improved" website previously hadn't worked with NS 4.5 on a Mac)
HOWEVER... miles from AT&T and FirstUSA (miles for visa purchases) don't appear/aren't itemised, and no flights beyond early February appear. Although I phoned BA and asked for a printed statement a month ago I am still waiting...
Perhaps, (to give them the benefit of the doubt?) they are in the process of updating their database... and to think that the UA ffs complain because their website is two weeks behind...