Is there a limit to the number of test friend requests that can be sent by a sandboxed Facebook app?

Been tweaking my app's invite process and sendin开发者_运维知识库g invites to two test accounts. They've worked fine.

In the last few days, my friend requests are not being sent out to the test users. Is there a finite number of times this can be used in a sandboxed app?

I set up another test app and a request went through okay.

In fb docs it says something about limits for invites, but it doesn't say whether or not it is true for the sandbox mode.

A user may invite a number of people each day equal to the maximum number of requests allocated to your application. If a user attempts to go over this limit, the following message appears:

_{(source: marketworks.com)}

Some interesting discussion is going on in this thread, looks like invite feature could be suspended if they detect fake users.