Well, it turned out that I posted too quickly on the assumption that, if IndigoPerl wouldn't easily install, I was going to run into mucho problemos. SiePerl did install easily (that's not a slam at IndigoPerl, by the way).
in reply to How to have multiple Perls under Windows
Apparently, the way you do this is, put the other perl somewhere else and then call it with the full path name.
Seems like I've heard that somewhere before--oh, and it didn't fix my problem. Neither using two different Perls to run the client and the server nor using SiePerl for both eliminated the blocking.
They laughed at Joan of Arc, but she went right ahead and built it. --Gracie Allen