When printing a standard size 10 envelope with a return address, I get a
large black line (about 3/16in.) down the left side of the envelope.  If I
omit the return address there is no line.  If I delete the return address and
print with the return address field blank it will print with no line.  If I
print with any characters in the return address field I will get this
obnoxious line.  

Also, this is a new development.  I recently added an APC battery back up,
but uninstalled the software a few days after installing it.  The APC monitor
seemed to be interferring with the wireless adapter monitor.