first, many of the banking sites require more secure browsers to access their sites. I have experienced that, though not with BOA. However, users having problems accessing BOA has been mentioned on here many times in the past year, and I have seen them install and use Opera Mini.
--You might try changing your browser emulation (Browser > Options)
--You might determine if you accessing the BOA mobile site (if they have?)
--You might install Opera Mini
http://www.operamini.com/download/
And you can always search the board here to see exactly what those other users reported. Good luck.