Safari 5 and tabs/returns

Safari 5 seems to handle tabs and returns differently (as well as entry from a numeric keypad). I use an on-line grade book program, and when I try to enter grades, tabbing and returns move to different fields in the title bar of Safari rather than to the next field in the grade book spreadsheet. Is there a way to disable this?
Safari 4 did not have this problem.
Thanks for any help!