I have X2, X3 and now Sonar Platinum all installed on my computer.  I completely loved sonar X3 until I started using UA plug ins and now its unusable.  So I bought platinum thinking the problems would be fixed, some were some were not.  It crashes a lot now.  Every time I open a UA plug in, the sound engine stops and it routinely crashes 5-6 times per session.  Prior to UA I almost never crashed.
 
I never use the old versions of Sonar, so I thought maybe having less "stuff" on my PC would clean things up a bit, maybe even thought that would help, but I am afraid to uninstall them for fear I'll make things worse.  If you have an upgrade version of Sonar and you uninstall the older versions does it do anything bad to the newest version? 

No the opposite.The general concensus is it's much better if you keep it I stalled. Don't touch it!

Get you UAD firmware and plugins/drivers updated.. Get your audio interface drivers and firmware updates. And your motherboard BIOS and chip set drivers. Also run windows update several times.

rcalligan
I have X2, X3 and now Sonar Platinum all installed on my computer.  I completely loved sonar X3 until I started using UA plug ins and now its unusable.  So I bought platinum thinking the problems would be fixed, some were some were not.  It crashes a lot now.  Every time I open a UA plug in, the sound engine stops and it routinely crashes 5-6 times per session.  Prior to UA I almost never crashed.
 
I never use the old versions of Sonar, so I thought maybe having less "stuff" on my PC would clean things up a bit, maybe even thought that would help, but I am afraid to uninstall them for fear I'll make things worse.  If you have an upgrade version of Sonar and you uninstall the older versions does it do anything bad to the newest version? 

Maybe it's time to troubleshoot your system. Having multiple Sonar versions on your computer won't be what's causing problems with UAD. As far as I know the latest UAD version work perfectly well with Sonar Dorchester.

You run the risk of breaking something in the latest version by uninstalling earlier versions.
 
Unless you are REALLY short of disc space (in which case a new. bigger hard drive is in order), leave it as it is.