Here's an item I discovered to my chagrin the other day...
 
I have a track setup with BlueTube PEQ2-3 feeding into Amplitube 3 with no internal fx (only amp/cab modeling +mic) inserted in the FX Rack and then using ProChannel devices (set to POST FX-Rack pc76/QuadEQ/Softube Saturation/Tape Duplicator/Console Emulator).
It is feeding into a bus that has ProChannel version of Breverb 2...
 
I added the Sonitus DDL after Amplitube 3 and enabled Record as well as Input Echo and after a short time passing, CbB suddenly will lockup and crash! Further experimentation showed it to crash with the enables too!
 
So I moved the DDL to an Aux send and there it works fine... No crashes...
 
I hadn't experienced this before as I usually use a send, but it was easier at that moment to insert it into the FX-Rack...
 
Has anyone else experienced anything similar?
 

It's funny that you mentioned Blue Tube. I loaded a project yesterday, and the project generated a fault report and crashed Sonar. I closed everything opened it up and started to work on it, Opened up Blue Tube Brick Wall limiter and it worked , but the meters weren't moving unless I hovered the mouse over the knobs and clicked. Are the Nomad plugs no longer supported? I went to try a different one, but they weren't in my plugins browser. They are on the machine and scan (because I have that location set up to scan) I don't get get any failure reports, so what gives? I can live without them, but I do like them and have had good results over the years. I wonder if your problem is related to mine?
I should add that the brick wall was already on the project , on the master bus. I did not go searching for it, just happened to begin to susspect problems when I saw it behaving oddly.

Interesting...

I don't think it's related, but I won't rule it out.

Maybe if i took the blue tube device out of the bin and left the sonitus ddl it might work fine?

If I find the chance I will try this out of curiosity... I'm fne with my more "normal" approach but I thought to mention and question the situation.

I don't know why your blue tube devices aren't showing. Check which menu you're using? All mine shiw up fine including those bundled with Sonar as well as others I own...

Check the .DLL version. There was at least one version released that had a memory leak that would eventually cause a crash:
 
http://forum.cakewalk.com/FindPost/2171195 (post #5)
 
"3.3.3.141 that came with the 8.5 physical kit was the bad one, and all others (specifically 3.3.1.298, 3.3.3.221, and 3.3.3.372) seemed to be okay."

Thanks brundlefly...

That makes sense and I remember the issue through my fog of age now that you mention it.

I'll take a look, but I think I remember updating it when that fix came about...

Nope...
 
I'm running v 3.3.5 it seems...