Agile Discussion objects become corrupt when someone clicks the Join button

Hello,

We have a template for creating Agile PPM Tasks. We have an Event Handler script tied to it such that when someone creates a new Task using that template, the script creates a Discussion object on the Task's Collaboration tab with a Subject that contains the Task's Name and Number.

As soon as someone opens the Discussion and clicks the "Join" button, the Discussion becomes corrupt and can lo longer be opened. Trying to open such a Discussion produces a message:

Application Error

This feature did not perform as expected. Please contact your Agile Administrator.

Strangely, manually created Discussions on the Collaboration tab of the same Task object work correctly.