Midi issues

The other night I was goofing around with a cover song I recorded and decided to try an add some of the FX the original song has in it. At one point in the song a synth comes in and the "Ahhh male and female choir" in Dimension Pro works fine, but the FX will last only a couple of seconds. In the original that one "ahh" lasts well over a minute.
 
So, my question on that is, how can I make that one note last for a defined amount of time? When I click on the note in piano roll it has an option for duration and the color marker does extend out to that amount of time, but the actual note still only lasts a couple of seconds. I've exported the sound to a wav and pieced it together like a loop, but it sounds kind of cheap.
 
Also, when I first edited the midi in that project I was able to draw out the notes and where I wanted them in the piano roll. The next night I wanted to add to it, but it would not let me. Any known reason why?
 

I can't find anything that is preventing it from carrying the note. I guess I'll have to buy a different choir plugin.

Paul P
 
I hit this same problem with these choir samples a while ago.  The problem is they aren't looped in the wav/flac file so they just play and stop.  I don't know how you were originally able to get them to sustain indefinitely.  In DimPro, I believe the looping mechanism only loops the envelope, it certainly doesn't loop the sample.
 
You can add a loop to the wav file using a wav editor (or maybe a loop in the sfz file I can't remember if I also tried that or not).  As you discovered this can sound pretty bad and I never spent the time to find good loop points.

All I did was play the note until it stopped, exported it as a wav then imported that back in and just copy and pasted it trying to make it sound as fluid as possible.
 
I downloaded a demo of a Choir vst called Magnus Choir. It doesn't seem to want to work with the latest Sonar. I've used it before with X1-3 and it was fine.