ARD report always "Waiting/Generating Report" WHY?

I am getting way to many systems that are failing to show anything in the ARD Reports function. New systems most often just show "Waiting" forever or they may go to "Generating Report" and sit there for more than a day.and never do provide a report. Other systems will show a report date of anything from several days to several months ago. These are almost all (250 or so) assorted iMAcs, MacBookPros, Minis, and MacPros running 10.8.4 but a few 10.7 and even 10.6 systems exhibit the same behavior. The ARD client is set for full control including reports. Assorted times for gathering the reports show no difference in response. These times may range from the default midnight to 1:00 PM so systems may be on or off line for all seven days a week. The times were set either when the systems were first entered into ARD. Some were changed using the "Get Info" Reporting tab but going either way makes no difference.

Because of the number of systems, I am extremely reluctant to do a complete uninstall, including the database files, and reinstall for fear of not having the info even come back on systems that I do have old but still existing info on.

I know that this was a problem a number of years ago but since Client 3.6.2 (and using Admin 3.6.1) this problem has grown substantialy worse. Anyone know what the cure is?

What I might do is put the ARD Admin on a different, and completly clean, system to see if reports can be generated there. If I can do that I will update this entry to show the results.