Thanks. I'll be checking back on this thread to see how it works out. Also, unrelated, VE Pro has been crashing on me when I try to change the colors of the channel strips (for consistency with colors for instruments in Logic).
Well, I gave it one more try. I closed everything down and restarted my machine. VI Pro Standalone worked fine. I then loaded Logic and the music I am working on with the VE Pro instance in it that loads the VI Pro Instance of cellos. Still no luck -- keys are dark in legato within this instance. I closed that project.
I then opened a new, blank project within Logic 9.1.3. I first instanced VI Pro by itself and loaded the patch in question, SE, Orchestral strings, cellos. Legato loaded fine. I opened a new track and instanced VE Pro multi-trimbral and loaded ONLY VI pro within VE Pro. The patch worked here also!
I closed my test composition and REOPENED the one that was not working. I deleted the Cello channel within VE Pro and then opened a NEW VI Pro instance to replace the one I had deleted, loading the SE cello patch. It ALSO worked! I plan to use this one until whatever is going on is figured out. Thanks for your prompt response to the problem.
Steve