Internet Explorer 7 [1] is still in beta, but we have been happy with it so far. If you are having troubles with Internet Explorer, you may want to give version 7 a shot.Also try Firefox [2] and Opera [3]
Links:
[1] http://www.microsoft.com/windows/ie/ie7/ie7betaredirect.mspx
[2] http://www.mozilla.com
[3] http://www.opera.com
[4] https://www.paypal.com/cgi-bin/webscr?cmd=_xclick&business=rick@yourpcpartner.com&item_name=Buy