ITA Discovery never completes. freezes at 99%

I am using IT Assistant version 6.5 BLD_65061.  I have it installed on three servers (PE2650, PE2200 and PE4400) and four workstations (OptiplexGX270, OptiplexSX270, OptiplexGX150 and a Dimension2350.)  On every installed machine the network discovery gets to 99% complete and seems to hang there for days at a time.  Each machine is scheduled to perform a scheduled discovery every four hours and a status poll every hour.  Although the discovery feedback indicates that the last discovery got to 99% complete and just stops.  Left alone for several days the discovery never runs again until I do a forced discovery, or reboot the system.

I've adjusted the range of each discovery range, I've deleted some ranges altogether, I've done discovery strictly on machine names, no matter what I do it hangs on the last range it got to at 99%.  I've got some machines that only discover a single range, they hang on that range.  I've updated SNMP on the ITA machines, and I've uninstalled and re-installed all of the OpenManage software.

(I use ITA on the desktops merely for wake on lan in the different subnets.)

Is this a known problem?  Is there a fix or patch?