I never had this problem since i installed the Dorchester. any time i press record during playing midi tracks it cuts the sustain of midis in playing and become normal in the next entry(note).For example I am playing a loop from RMX which is 4 bars and the next track i want to record is piano , as soon as I press record , it won't play the RMX till 4bars passes and will play the second 4bars which is the new entry.I hope I did explain it properly
Thanks for any help.

I noticed midi notes being cut off when input-enabling audio input tracks. Related? I don't know. Doesn't seem right, though.
 
When you say won't play till 4 bars passes, is that a loop with many notes or just long notes that start at the 4 bar boundary? In other words, are there some notes in your midi loop not being played at all?

bvideo
I noticed midi notes being cut off when input-enabling audio input tracks. Related? I don't know. Doesn't seem right, though.
 
When you say won't play till 4 bars passes, is that a loop with many notes or just long notes that start at the 4 bar boundary? In other words, are there some notes in your midi loop not being played at all?

Thanks for your reply. Yes it is a loop with a long note . 
I tried with a new project and just loaded a simple piano and recorded just 1 long note in 2 bars. now when i go back and want to record another note in the same track on the previews note that I already recorded it cuts the last note as soon as i press record or even pressing cont+C to copy. I can say any activity during playing any long midi note will causes cutting the note.
Also type of recording is sound on sound. 
 

I rolled back to cambridge and problem solved. So it means it is a bug in the new update.

REZA
I rolled back to cambridge and problem solved. So it means it is a bug in the new update.

Report it.

Just so everyone is aware - this has been reported internally. No action is required by anyone in the thread at this time. Thanks for bringing this to our attention!

This is the workaround I've got from very helpful Mr. Joey Adams from Technical Support.

I tested your procedure and found that this does indeed occur in the latest (Dorchester) update only. I have forwarded this information to our development team so that this can be addressed in a future update of SONAR. However, for now, I would recommend that instead of using the Record button in the middle of playback, you simply click the Record button (or press "R") from a Stopped state.

I can name it best ever studioye joke  even in old fashion 8tracks tape you could press record when you were playing . 

REZA
I can name it best ever studioye joke  even in old fashion 8tracks tape you could press record when you were playing . 

 What can I say. We should be 'upgrading'. It seem like we are kinda 'downgrading'.

Joey Adams [Cakewalk]
Just so everyone is aware - this has been reported internally. No action is required by anyone in the thread at this time. Thanks for bringing this to our attention!

The moustache needs fixing!