cant add users to vo

chaps

this morning ive been doing a bit of housekeeping on VO (deleting users etc). When it cam to add a couple of new users i fill out the form on the 'add user' page and click submit and all i get is 'error on page'. This in turn shows....

line:137
Char: 1
Error: object doesnt support this property or method
Code: 0
url: https://xxxxxx/vo/jsp/adminSignup.jsp

Ive re-booted the VO server but this didnt help. Hope you can assist

cheers
Ojo