I asked this in another thread but it's buried 20 posts in.
 
In Win7/X3 when I do rudimentary midi tasks such as drag-and-copy, split clips, quantize a clip, transpose a clip, move a clip, etc, I get the spinning blue wheel for what I estimate is maybe 1/4 second.
 
The wait of ~25ms isn't a problem but what this means is I can no longer perform these tasks during playback without a jump/glitch happening in the audio.  In Vista/8.5 these tasks happened instantaneous to my perception and caused no jump in audio during playback, I could edit midi and audio seamlessly during playback.
 
I just want to know, is this inherent to X3 or is this something in my system I need to figure out and fix?  Thanks for you time.

No wait time for editing tasks for me.
 
As for editing during playback, I don't normally do that. But just for a simple test, I tried the following during playback without any problem :
- insert a midi track
- ctrl-c a midi clip
- ctrl-v on the newly created midi track
- since the now-time is moving, naturally it'll copied at the wrong place
- drag the clip to position
 
Have you checked your system ?
http://www.thesycon.de/deu/latency_check.shtml

Is that safe to download?  I always hesitate to download anything unecessary.  My latency seems to be fine.  The pause happens on midi and audio editing that I'm not used to seeing coming from 8.5.

The download is safe, it's widely used by forum members.
 
 
Although might not be related, you can also try
http://support.presonus.com/entries/21588398-sonar-64bit-audiobox-1818-no-playback-after-driver-update-solution
 
You may want to copy down some settings you might have changed and update it back later.

For the record, an instance of Vienna Ensemble Pro Server was causing this.