I'm currently using the 6.x-1.x-dev version with Drupal 6.16 and as admin when I delete a user from the Default relationships list the below error pops up.
"recoverable fatal error: Object of class stdClass could not be converted to string in /home/.../sites/all/modules/user_relationships/user_relationship_defaults/user_relationship_defaults.module on line 194."
Tried a complete wipe of all UR tables and reinstall of the module but still happens. If I remember correctly this didn't happen when using 6.x-1.0-rc3
If doesn't seem a serious error as I can still proceed past it but still a little disconcerting to see it.