Intermittent Installation problems

I use XP SP3 with Firefox 3.6.13

I have a master domain and several add-on domains and am in the process of installing wordpress on each of these add-on domains.

So far I have completed 6. All installations appear to be successful in that I have received a “success” message plus a confirmation email.

However when I try to login the position differs. On some domains I login without problem but on others I get the error message:

“The page isn’t redirecting properly
Firefox has detected that the server is redirecting the request for this address in a way that will never complete.
* This problem can sometimes be caused by disabling or refusing to accept cookies.”

I have checked the latter and this is not the problem.

I have also checked each individual domain and all websites load and display correctly.

Has anyone any idea what my problem is and how I can resolve it. All suggestions appreciated. Thanks in anticipation.