Fill the "conta" textfield in the top of the page with 4 numbers (0000) then hit Tab to go to next textfield, then an alert will be shown saying that you must type only numbers.
Confirmed with a local debug build of WebKit r21856 with Safari 2.0.4 (419.3) on Mac OS X 10.4.9 (8P135). Also occurs with shipping Safari on Tiger (see versions above). Not only does it intercept tabs, but also Cmd-W and Cmd-Q! Works in Firefox 2.0.0.3 (tab, Cmd-W and Cmd-Q). Needs a reduction to determine if this is actually a WebKit bug or whether the site needs evangelism.
Note there are error messages printed to the JavaScript Console when loading this page: Unsafe JavaScript attempt to access frame with URL http://www.bradesco.com.br/ from frame with URL http://institucional.bradesco.com.br/relogio/relogio.html. Domains must match. Line 1
See also: bug 13031.
Created attachment 17673 [details] reduction
Working on a fix.
Fixed in revision 28620 - we now match IE and no longer dispatch keypress when tabbing between input fields.