Firefox redirects in MAMP environment



On my MAMP environment I have an installation of MU and a number of sites running wordpress intallations and a joomla, mambo etc. They all open in safari. The MU was set up by setting up a virtual host

The MU site, worpdress sites and all the non wordpress sites open in firefox, but only the MU, joomla, mambo etc., and a few of the wordpress sites open normally. The other sites give an error message, "The page isn't redirecting properly".

I've spent a great deal of time on and off for months trying to figure this out and really have no idea what is happening.

Does any one have any ideas?