Version 23.7.0 Build 37
 
The anomalies I can recall at the moment:
 
1. Audio dropouts. I used to almost never get these. Now I get them even when making only light demands on the computer. I also experienced at least one dropout while NOT using Sonar...while simply playing a .wav file. So maybe I need to not blame Sonar for this.
 
2. Today I played a series of chords into Sonar via MIDI. When I viewed the results in PRV, there were 2 of each note. For example, I played a C chord and there were 2 c notes, 2 e notes, and 2 g notes, one on top of the other in the PRV. Two of each note in the exact same location.
 
3. I was using an 8-bar acid loop, but decided I liked bars 1, 2, 7, & 8. So I deleted the unwanted middle portion and then tried to slide the end bars forward in time to meet the beginning bars. Nope. I could not bring the section forward. It wouldn't budge. I then disabled the grid and was able to slide the clip forward to the approximately proper position. I then re-enabled the grid so I could exactly position the clip at the start of the desired beat. But when I then selected the clip and dragged left, it instead went back to its original position 4 bars to the right. 
 
It could be that only some or perhaps none of these are related to the update, and it's just my turn to sit scratching my head.
 

I was having weird dropouts after the latest update also.  I changes the buffer(latency) setting on the Audio Card, then put it back to where I wanted...rebooted and I'm back to normal with no drop-outs.  Don't know if i fixed anything, but hey, I'm workin' again.

Yep, I'm getting more Sonar freezes with 2017.07 (has something to do with MIDI but I don't know what - YET). My cursor now leaves trails (like I used to see in the "old days", just less colorful!) and everything just feels sluggish and less responsive generally (although I can't measure that).

I was getting audio dropouts as well after this latest update. The dropouts would occur within 5 to 10 seconds of Launching Sonar, and would occur while Sonar was idle. I could reproduce this every single time on program launch.
I experimented with Buffer changes, checked the net for solutions, but nothing seemed to work.
 
I have an Nvidia GTX 770 video card, and along with the cards graphics driver there is also an "Nvidia High Definition Audio Device" driver. I disabled the Audio driver and the dropouts immediately stopped. On re-enabling the Audio driver the dropouts came back.
 
I upgraded my GPU & the HD Audio driver to the latest versions and I haven't had any more dropouts. This may or may not work for anyone else but if you have an Nvidia Geforce card it may be worth your time to update to the latest drivers.  

On the double MIDI notes being recorded, make sure you don't have MIDI echo enabled anywhere, either in SONAR or on your keyboard.  Also, make sure the MIDI track's output is not set to the same MIDI out and channel that the track's input is set to.

I was guessing there might be a change in the wave form drawing that is hard on IO. This would explain the disc activity and the dropouts.

I was guessing the devs all have SSDs so they missed the impact while improving touch zoom.

Wave form work can be heavy when opening a project.