customer registration freezes up

while our site has been live for almost two month, we continue to have sporadic transaction errors.  examples follow:

1.  customer place their order then goes to register and they are froze on that page.  they hit the 'register' button and nothing happens.
2.  a customer registered, placed their order and then went to enter a different mailing address and the site freezes up.  

we turned off the registration as a requirement for placing an order but that doesn't seem to make a difference.  we changed hosting companies - from godaddy to a private host and that doesn't appear to have made a difference either.

its very frustrating to think about all the missed order because of the site freezing up.

i look forward to any and all advice we receive!  thank you!  cindy

I am having the same problem. Can someone please help?

A) Always post the version you are using.

B) What does the log file show for errors?

C) Possibly you may wish to show the URL.

Found the problem.
uncheck Allow navigation only for registered customers: in Global Settings -> Other. Then clear the cache.