[Plugin: WP-Invites] Causes posting problems

I installed this…signed up a test account & it worked. I tried to register without a number & it stopped me just like it’s supposed to. I added a couple of more plugins…tried to post something & I’m getting:

Your attempt to edit this post: “lkfjasl;kjfl;asfj” has failed.
Please try again.

Trying again gets me a duplicate. Pages…posts…it’s all the same. So I took off 3/4 of the latest mods & fixed it. Put yours back on & it’s ok until I attempt to allow registration (otherwise I imagine even invited people can’t register). Go back to post something & it won’t let me. I hope you can fix it cuz I can’t get the other invite plugins to work either.

http://wordpress.org/extend/plugins/wp-invites/