I've been having this problem, except it seems to have to do with the database; so I put in a fresh version of zen to start over.
I tested the create an account and it worked fine.

Then I loaded my template files, this is where the problem started again.
I make a new account and when I hit submit I get the error:
1146 Table 'seasecom_zc2.TABLE_SUBSCRIBERS' doesn't exist
in:
[select count(*) as total from TABLE_SUBSCRIBERS where email_address = 'swtjes##################' ]

I'm trying to put my current store on another server. I've got my template design which is the only part I've been copying over to the fresh install. I checked the database on the other server and the table zen_subscribers was not in the fresh install, I copied it in and it didn't make a difference. I don't want all the other files, the person who designed this site made it very difficult to move, I've moved it once, but the new host moved it for me.

The current site it's on is www.joyoushome.com/store

The new server I'm trying to move it to is:
The url is www.s e a s o n s a t h o m e m a g a z i n e .com/shoppe

The only other files I've been playing with are the lightbox and IH2 handler which don't seem to be working right but whatever, if someone can't make an account it wouldn't matter

Thanks for any ideas on this, Theresa