Sequencing errors are easily induced in v2.2.2 od9b96 as follows:
While in a QSO with contact one, double-click in the left window on another contact then immediately double-click on the last received transmission from contact 1 in the right window.

If this action is taken following a received RR73, a 73 should be sent but isn't.
Instead, an RR73 is sent.

If this action is taken following a received initial signal report, the correct R+ signal report is next sent but then does not advance to the 73 message after receiving an RR73 and instead remains stuck sending another R+ signal report.