Customer Can't signup after installing new theme

[snawaz]

their is 2 files

1 index.html
2 index.php

[picandnix]

their is 2 files

1 index.html
2 index.php

Ok, so no error files are being generated.
I'm at work at the moment now but I'll happily take another look at the problem for you later.
In the meantime, what other mods have you installed, and did you compare and merge the template files to your existing files as you installed them?
Did you have any other templates installed, other than the default green one?