This is a brand new bug for me but I can reproduce it every time.  So weird.
 
On a fresh boot I open Sonar and all is fine, I can run it for a few seconds or a few days and everything works great.  Now if I close and re-open Sonar, whether manually or if Sonar crashes, the second time (and every time after) I open Sonar it is super sluggish.  For example, 30-40 seconds to load a project instead of the usual 5 seconds, then noticeable delay of 2-3 seconds on everything that's normally instantaneous such as opening a track folder or moving an audio clip, etc.
 
The only way I've found to fix it is to reboot and reopen Sonar.  It is always fine on fresh boot, always sluggish on 2nd opening.  I've never seen anything like this.... any ideas?
 
I can reproduce the bug whether or not I open anything else on the computer such as email, browser, etc.  In fact I can reproduce it simply by opening Sonar on a fresh boot, loading a session, closing Sonar immediately, and reopening it.
 
I don't get any error messages when I manually close Sonar, it looks fine.
 
I'm on X3e and Win7 Pro.  Any thoughts?  Thanks!

Opposite behavior here.
 
First time: 5 secs to start screen, another 10 for opening a project. Stuff like VST scans and screen buildup happening.
 
Close Sonar X3e
 
Reopen - 3 secs. Open same project, 2 secs. Screen buildup nearly immediate. No VST scan in background.
 
Win7 64bit home premium, Acer Aspire i7, 4GB, 750GB magnetic drive, Cakewalk/Edirol UA-25EX interface.

Ah, correction: VST scan DOES occur.

Maybe check any resource/performance/hardware monitors.
 
It almost sounds like Sonar is loading up something somewhere that is refusing to fully release itself so when you reopen it it's fighting with that old session info.
 
Maybe a failing stick of RAM? Disk Sector (cache memory)?
 
I am not a tech and just taking guesses but yeah... sounds hardware related especially if it's a new issue and you haven't changed anything on the system.
 
Or maybe you caught a virus?

Temp disable your virus scanner... Any different?

I've also got pretty slow project load times, minimum 20 seconds, for larger projects 30 to 45 seconds. This is with virus checking turned off. I'll have to check my event log for hardware issues I think.

Another thing. After you close Sonar for the first time check to see if bitbridge or Sonar is running in task manager.
If you are using 32 bit plugins stop using them to see if this makes a difference.

Yeah I always check in task manager to make sure Sonar actually closes, on occasion it has not but recently it always looks to close fine.  I don't use any virus protection.... or bitbridge or any 32-bit VSTs.
 
5 seconds load is pretty typical for me, I don't like to wait for things.  All of my projects are pretty straight-ahead the only plugins being one instance each of kontakt, stylus, omnisphere, and zebra, with no patches loaded.  I run everything on 6 slave computers over MIDI.
 
But I would tolerate 30-40 second load time if Sonar was actually working, which it isn't.  On the second and subsequent starts, that is.