I've written before about troubles getting Linux to work in a Windows world. Today, it occurred to me to try something I dimly remembered: getting Firefox to pretend to be Internet Explorer using a plug-in called User Agent Switcher. It's an easy download. Then I restarted Firefox, pulled down the Tools menu, and went to Default User Agent>Internet Explorer>Internet Explorer 6. Voila, I immediately had access to our payroll system.
Which means that, since the only thing this does is send a different string of letters to identify the browser, Firefox 3.0.16 is deliberately disabled by my vendor. Complaints to follow. Meanwhile, this was a MUCH simpler solution than the wine approach, which seems only to work SOMETIMES.