Hi All,
 
I'm pretty sure i'm being stupid here but i noticed something odd last night.
 
I'm working on a song currently, bass, drums, synth, couple of guitars, the usual. All is fine. Last night i started recording vocals. I have 3 vocal tracks. The first 2 are basically a 'double' of the lead vocal, the 3rd is a backing vocal track with some harmony etc.
 
Now then.... When i solo'd the 1st vocal track i realised that i could here the output of the backing vocal track as well as the vocal recorded on the 1st track.
 
I'm guessing this has something to do with the fact that i have a send on all 3 vocal tracks to the same reverb bus? But i THINK i have the reverb bus outputting the master bus and the master bus outputting to my audio interface, so this surprised me.
 
Any ideas?
 
Thanks in advance.

Turn "Exclusive Solo" button on and see if that works. 

Do the other tracks/voices become silent if you mute your Reverb bus?
 
This has to be a routing problem somewhere.

'Dim' solo button engaged in the Mix module? Or possibly the sends to reverb are Prefader, but you wouldn't usually want that, and it would be obvious that you're only hearing reverb.

If Benjamonk is hearing other vocals while the single vocal track is soled, he must have Exclusive Solo engaged. 
 
There are several situations where soloing one track actually solos more than one track, even when Exclusive solo mode is enabled:

1. If you solo a track folder, all tracks within the folder are soloed.
2. If you solo a track that is assigned to a soft synth, all other tracks that are assigned to the same soft synth are also soloed.
3. If you solo a track or bus that belongs to a Quick Group, all other tracks or buses are also soloed.

So if he has all of his Vocals going to the same bus and the soloed track is in that bus then the Bus is soled as well.
 
I believe Benjamonk's problem is number 3.

Many thanks for the replies.
So, here's the weird thing. I booted up sonar last night and loaded the exact same project. The first thing i did was solo the same track and hit play back. Guess what? All i could here was the audio from the vocal track, which is excatly what I should be hearing.
I didnt do anyting different to the night before. Did sonar just get 'confused' somehow? 
The project is in exactly the same state as when i left it, so no routing will ave changed.
Has anyone else expereinced this at all?
Anyway, thanks again for your input. The problem has resolved itself for now at least.

I'm glad it's resolved but like an old bloodhound, I'd really like to know what caused it and what rectified it!
 
I've never experienced this before, it's certainly not normal behaviour

Yeah me too. I'm going to keep an close eye (and ear) on this from now on and see if / how / when it happens again. If i learn anymore, i'll be sure to share the details.

There  are three solos in Sonar. Solo which is the one most use. It is able to solo more than one track by soloing other tracks. To unsolo a track one must toggle the solo button on the track/s you want to mute. 
 
Exclusive Solo. This will solo a track and one can quickly solo another track without having to unsolo the previous soloed track. 
 
Dim Solo.  It lowers the level of all non soloed tracks so they can be heard but much lower. There is a setting for how loud you want the dim soloed tracks to be. Its in Preferences Audio Driver Settings. The mode you use for solo is set in the Mix module.