Piano Roll weirdness

In the Piano Roll, if I navigate by clicking the measure/timeline, all sorts of weirdness is happening. Sometimes it just ignores me, other times it's OK if I click at any point before about 5:01:000, after which it will always jump to somewhere around measure 14.
 
If I go to the event list all is well. It's also fine in the track pane.
 
The only thing I can think is that I actually copied the events from another song and then pasted. AT first Sonar saw one of the tracks as an Audio track, then when I created a MIDI track and pasted in the offending events, SONAR now says it's a mixed Instrument and MIDI track.
 
So, what next :(
 
Appreciate any help here.
 
EDIT:  I deleted the track that says it's both MIDI and audio and the behaviour did not get better