I've seen this problem with X2 and now with X3e.  After recording a MIDI sequence to audio the wave file has visible gaps in it and also vertical lines where tempo changes happen.  This does not affect audio recording or playback, those are fine, it is purely a graphics issue, but still annoying.  When I zoom way in, the waveform begins to appear normal.  If I export the wave file to Sound Forge, it looks perfectly normal there too at any magnification so the problem is specific to Sonar. 
 
I've tried emptying out the waveform cache and also recalculating the waveform, but to no avail.
 
I am wondering if this problem is specific to my system or if others have noticed it. 
 
Jerry
www.jerrygerber.com
 
 
 

Seen this and as far as I can work out it is to do with tempo changes.  I guess the reason it does not occur in Soundforge is because the tempo changes have become "embedded" in the tune and are irrelevant to the the wave form created by Soundforge.