Acting on a hunch, I think I've tracked down the source of the 100% CPU
usage creep (and amazingly, it isn't my code!).

I think the problem is caused by the usage of the Speaker class.  I've been
using Speaker for audio feedback in one of my classes and this co-incided
with the strange 100% cpu usage problem.

This morning I started up two VM's...one VM has my serial-polling class
running (without any Speaker usage).  The second VM is sitting idle, with
one important difference:  after I started it, I did several
Speaker man say: 'this is a test'.  After that, I left it sitting idle.

When I left for work, VM number 1 was sitting at a constant 8-10% cpu
usage.  VM #2 was up at 20% (sitting idle, remember!).  I just checked
the CPU loads and found that VM 1 hasn't changed, while VM 2 has creeped
up to 38% CPU usage.

I'll check things once I get home from work...but I think I'll find that
VM 2 will be in it's 100% CPU dead state.