Hi. I wonderd if anyone can help me. ive installed joomla, but when i try to create a new user, I recieve this msg: "Could not instantiate mail function".

The reason you are encountering this error is becuase it is requiring use of the PHP mail() function which is turned off by default in the Zymic Hosting Accounts.
However, you may enable this function for a one off fee of $10 by speaking to one of our staff on the IRC.

Jacob.