Please break up
into two parts (steps.)
The first step should just have
Email address: ________________
and then a [Submit] button.
This should then return a second page with all the remaining questions,
and a final [Submit] button.
Users may have forgotten that long ago they already registered an account.
Checking if thier email already is registed first will avoid them
needlessly filling in all the registration questions, only to find out
they have already registered.
Especially for older slower typers the savings would be great.