System Center consultant here. I'm in a lot of environments. Came across this today while running a report for Windows 7 Logical Disk details:
The EXECUTE permission was denied on the object 'Win7DiskUtilizationDrilldownReport', database 'OperationsManagerDW', schema 'dbo'.
Update to SCOM 2007 R2 CU6:
Don't waste any time trying to fix this via SQL. I've tried. The problem is deeper than that, and the hotfix installer takes care of it all.
UPDATE: Yes, you do have to fiddle with SQL:
You need to check the following stored procedures and give the appropriate accounts EXECUTE permission:
Win7ClientPerfMachineReport Win7DiskFailureDrilldownReport Win7DiskFailureDiskReport Win7DiskUtilizationDrilldownReport Win7MemoryFailureDrilldownReport Win7MemoryRAMReport Win7MemoryAppDrilldownReport Win7MemorySufficiencyReport Win7ShellPerfMachineReport Win7ShellPerfMachineDrilldownReport
Looking at the stored procedures, there are actually a lot of Win7 specific defined. I granted Execute to my reader account. Credit goes to http://www.systemcentercentral.com/tabid/60/indexId/77557/tag/Forums+Operations_Manager/Default.aspx for the fix.
UPDATE: Some reports are still kind of funky. It turns out my DW Reader account did not have local admin on the Report server. If you still have problems with your Win7 reports, this should take care of it!