After installing Mozilla Firefox 3 beta 4 on the Microsoft Dynamics CRM 4.0 VPC image and browse to the CRM 4.0 url, you get the following picture:
You need to install the IE Tab add-on.
Install the IE Tab add-on.
Browse to the CRM 4.0 url and logon to the website.
Click on the screen with your right mouse button and select the option: View page in IE Tab and VOILA!
N.B. Please note that Mozilla Firefox is still NOT supported by Microsoft!