I'm having the strangest midi issue but I'm sure it's my fault. I drag a midi pattern from BFD3 into a Sonar midi track, then I drag in a variation of that pattern a couple measures behind the end of the first pattern. They look fine and play fine. When I drag the first pattern right to the second pattern things get weird. As soon as the two patterns are placed on adjacent measures a bunch of duplicate patterns are created and they extend for more measures than the original 2 patterns combined. For example 2 patterns of 4 bars in length are brought together and 12 bars of the same patterns are automatically created after the second pattern.
 
To make things worse, if I drag the first pattern back to its original location even more patterns are created down the time line. I don't use midi very much but I don't ever recall something like this, so I must have something messed up in my preferences. ANy ideas?

Is the Track View Options > Drag and Drop Options set to "Slide Over Old to Make Room"

I have that selected in preferences, plus I've selected align to measures. I just don't see how it can automatically replicate a midi clip, simply by touching two clips together, and creating more clips when you drag them apart.
 
If I immediately use the undo drag clip command it goes back to normal. If I try to manually undo the events it creates more clips.
 
I haven't done midi since Master Tracks Pro on the Atari. It seemed so simple.

What Steve was getting at is that Slide Over to Make Room has had a bug for a long time that causes adjacent clips to move too far and/or by random amounts, and to keep moving every time you reposition a clip. It's one of the few issues that has consistently been mentioned in the Readme doc. Like Steve, I suspected the behavior you're seeing is a side-effect of the issue with that drag 'n' drop mode. If you change the option to Blend, I'm guessing the replication problem will go away.

I get it. I've not used midi and tend to gloss over midi issues. Suddenly they're important. I've also found that the random clip behaviour was also creating take lanes. Two, four bar clips get banged together and produce 187 random bars full of clips and 17 take lanes with clips scattered randomly.
 
I think I should program the drum tracks inside the drum software and manage the individual drum outs in Sonar.Does this sound like a usable work around?
 
 

That's the way I handle drums. I use superior drummers interface for a basic mix and some processing. Each drum is connected to its own Audio track and then on to a Drums buss. I mostly use SupDrum to get the drum instruments sounding right and the Sonar tracks for mixing into the bus and over all project mix.