unfortunately this is quite pretty user experience with the Workshop module in Moodle 1.9. Please note that
- the submissions will not be allocated for the peers assessment before the $CFG->maxeditingtime period has passed (typically 30 minutes, it is the same period as users have for editing their forum posts)
- there must be enough submissions from peers to pick from
However I warmly recommend not to use the 1.9 version of the module at all. It has been completely rewritten for 2.0 and the new version seems to suck less (in other words, it has another sort of issues).