Thanks.   Did you activate "Search 1.8"?  Try that, clear browser cache, and see if you can register as a new member.

Hmmm ;-X
N/P here @ *localhost XAMPP with that scene.. ;- (
Search.1.8 + Browser Cache Cleared;
(2X) New Users register(s) OKI...
If U R having this as a problem...
I wonder what it might be ?
Server/Config or Browser Cookie cache.. ? OR ?

If you're getting a blank page, you should turn on PHP's display_errors option and see what the error is.

More info here: http://docs.elgg.org/wiki/White_page