Hi,
thanks for the nice assignment type. I'd like to report a bug when installing rtcollaboration. First things first, I'd like to say that I never ran cron before installing rtcollaboration (was a test server and I did not - at the time - have a pressing need for cron to run).
When I installed the assignment type and tested it, everything worked fine until I tried to run cron. It returned this error:

Server Time: Tue, 11 Oct 2011 14:58:09 +0800

Cleaning up stale sessions
Starting activity modules
Processing module function assignment_cron ...
Fatal error: Call to undefined function get_records_sql() in /var/www/moodle/mod/assignment/type/rtcollaboration/assignment.class.php on line 293

Call Stack:
0.0002 656104 1.

() /var/www/moodle/admin/cron.php:0
0.1118 23024744 2. cron_run() /var/www/moodle/admin/cron.php:85
0.2928 44322104 3. assignment_cron() /var/www/moodle/lib/cronlib.php:87
0.3013 45719960 4. assignment_rtcollaboration->cron() /var/www/moodle/mod/assignment/lib.php:2553
0.3013 45719960 5. assignment_rtcollaboration->submit_pending_submissions() /var/www/moodle/mod/assignment/type/rtcollaboration/assignment.class.php:299

Sure enough when I removed the assignment type, it was all back to normal and cron ran just fine. i tried reinstalling the plugin - same problem. Funnily enough, when I ran the 'notifications' page, no message was shown telling me something was being installed.

I wonder if anyone else has had the same issue.
Cheers,
Fred