I had searched just about every forum fro a fix. I tried all the suggested fixes to no avail.
I had recently upgraded my free avg from ver. 8 to ver. 9 .

S0, I uninstalled AVG 9.0, uninstalled my Lex x6100 driver software, deleted my printer, ran several regstry cleaners.
Disconnected my printer from the USB port. Restarted Windows XP Pro, created a system restore just to have it in this setup state.
Printer still not connected.
Ran my printer install software.
During the installation it say to be sure all printer cables are connected and if a windows install hardware pops up,
CANCEL IT!
That's what happened and I canceled it and clicked continue until all drivers were install. ( I did need to insert my Windows XP Pro setup disk to install a certain file and also go to WINDOW/System32/drivers to install one other file).
Restarted Widows. EUREKA!
No more "handle is not valid"
I am assuming that AVG 9.0 thinks that one or more of my printer driver files were viruses.
I reinstalled the older version of AVG. So far so good.