It has been a while since I have worked in LD 8.8 but remember there being some issues with policies and having to nuke the client side databases.
Have you thought about installing SP4 or moving to LD 9?
This is a script we used to clear out the client side DB and have it re-validate. You can test it out and see if if helps you... this is a XP only version.. create a .bat file and use Software Dist. to push it to client
net stop "Landesk Policy Invoker"
cmd /c del "c:\documents and settings\all users\application data\landesk\managementsuite\database" /q
del "C:\Documents and Settings\All Users\Application Data\LANDesk\ManagementSuite\landesk\files" /q
del "C:\Documents and Settings\All Users\Application Data\vulScan\*.xml" /q
del "C:\Program Files\LANDesk\LDClient\sdmcache\landesk\files\*.xml" /q
"c:\program files\landesk\ldclient\clientdbutil.exe" /create
"c:\program files\landesk\ldclient\clientdbutil.exe" /validate
net start "Landesk Policy Invoker"
EXIT /B 0
Thanks JM. I will give this a shot and let you know of results.