Sometimes, if I wish to load/open Sonar X1 (Win 7, 64bit, the program does not start). If I re-start the computer, and try it again, it works nearly every time. Sometimes the problem appears at the beginning of a session; but more often it appears, if I closed Sonar X1 and wish to start it anew. Do you have answers for that problem? Is there an update fixing that problem?

Your issue may be unique to your PC. I have not heard of anyone having this problem in X1.
Maybe 

the problem appears at the beginning of a session; but more often it appears, if I closed Sonar X1 and wish to start it anew. Do you have answers for that problem?

Most likely, something in your PC is hanging onto Sonar and not releasing it. check out your Task Manager


Cj

Sometimes, if I wish to load/open Sonar X1 (Win 7, 64bit, the program does not start). If I re-start the computer, and try it again, it works nearly every time. Sometimes the problem appears at the beginning of a session; but more often it appears, if I closed Sonar X1 and wish to start it anew. Do you have answers for that problem? Is there an update fixing that problem?

I'd guess the reason it doesn't open (the 2nd time) is that Sonarpdr.exe is still running in the background.
Next time this happens, check to see if it's running.  If so, right-click on it and choose End Process.
Now see if X1 opens...

@jim - yeah that's my problem usually.  you check by opening the task manager in windows and clicking the processes tab.  right-click sonarpdr.exe and select end process tree.