String section issues on Muse4

When downloading the different musical section sound section, they all downloaded perfectly except for the String upgrade (I think it downloaded about 85% and then stopped and I could find no way to get it to complete). When writing a orchestral new composition, I have been dealing with some sound and play back issues. The playback sound sometimes doesn't start immediately but instead after two or three notes have played. The metronome (measure playing bar/marker...sorry don't know really what to call the advancing blue line) isn't in sync with the actual notes being played. I'm wondering if any others have had this problem? and if so....any fixes or ideas on how to address these issues. I'd greatly appreciate any help. (Note: I'm a 70yr old...not exactly techie and find it difficult to keep up with the lingo..LoL!) Thanks....Marc