When adding a new web meeting, user is asked to enter use credentials for DimDim user account. After doing this and clicking the "Validate user Credentials" button to submit, nothing happens (the form is not submitted and page is not reloaded).

This happens with the version of this plugin downloaded directly from dimdim.com labelled "Moodle_v1.9_Dimdim_v4.5_Integration_Pack.zip" (see attached file).