Two contact record questions.

1.
I get a lot of m-crypt errors. When I go to edit details of a contact, for example, I get a full page of 
"[function.mcrypt-generic]: An empty string was passed in /home/..."

Sometimes, randomly, it seems, a line or two at the top of a page.
I'd like to use mcrypt, since I'm on a shared server. Anything that can be done?

2.
The other question is how can I share my contacts with other users? Can't seem to find that in admin/set up anywhere. Its probably simple, but I'd appreciate a pointer.
Thanks

JohnSent from the phpGroupWare forums @ http://forums.phpGroupWare.org