When I hit the space bar or click play in the tool bar. It takes 2 seconds for sonar to start!!!!!what is up with that??

For me this happens if I forget to turn the internet off. 
I then have to quit Sonar and open again for some reason and it goes away. 
When I get this behaviour it's global to all music software, not just Sonar. 
I thought something was really screwed, I re booted interface etc.. but in the end it was my network cable was still plugged in from last round of updates and I guess something was trying to phone home. 
After I unplugged this never came back again.. hope it works for you too..

WDM or ASIO?
 
WDM likes to do this to me when I've had to use it.

What's your buffer size? The most common reason for delays prior to playback is that the data is buffering. You won't notice it when buffers are small, but it can be noticeable with large buffers.

The combination of high track count and large disk I/O buffers can also slow transport response.

I am having this issue recently, also. Never used to be like this. I haven't changed anything.

This is most likely due to your buffer size being large and a large track count as bit says.  I routinely see this and it really isn't that big of a deal to me.

I had a problem like this when I had somehow set the metronome for a couple of count-in measures. At the same time the metronome was routed to a muted bus so I didn't notice it was turned on for playback. Not likely your problem, but worth checking just in case.

Count-in doesn't pertain to playback, only recording.

brundlefly
Count-in doesn't pertain to playback, only recording.

You're right, of course. They say the memory is the first to go. . .