Help me find a cross platform shared calendar solution!

Hello, I am calling on my fellow Kirupians for some help…

I work at a small multimedia company (3 ppl) and have been trying to get us organized with a shared calendar. I like Mozilla’s Sunbird but am having problems keeping it working…beta issues aside.

We don’t want to pay $100/yr for a .mac account (plus I’m the only one who occasionally uses a mac), so i’ve been TRYING to use www.icalx.com …Problem is, I don’t think anyone is maintaining icalx anymore. I’ve repeatively had problems logging in (even directly from the web site) or losing data. Even when I can log in, Mozilla’s password manager seems to work only occasionally, or it forces you to click “ok” on a dialog box everytime you need to edit the shared calendar…pain in the ***** (and too much to ask my boss to do)

Is there a FREE alternative to icalx? Is there a more stable alternative to Sunbird that uses .ics?

Thanks for any suggestions.