Please help me.....
My zencart hit problems last night and got in such a mess that I simply delete all the files from my domain and uploaded a backup which was made literally minutes before i messed the files up.
Everything seemed fine and i had no problems at all and everything works fine UNTIL a user logs in.
After entering log in info users hit a blank screen with the following text:

1064 You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '), customers_info_number_of_logons = customers_info_number_of_' at line 2
in:
[UPDATE customers_info SET customers_info_date_of_last_logon = date_add(now(), INTERVAL HOUR), customers_info_number_of_logons = customers_info_number_of_logons+1 WHERE customers_info_id = 1]

Im not techically minded in this way and have absolutely no idea of how to fix this error. The user can click back and will go back to the previouse screen and be logged in but there is obviously a problem and since this is a business site which is still relatively new i would rather start again now rather than later if this is unrepairable.

PLEAS HELP ASAP