Event ID: 4100 - Invalid pointer T

This is happening for a couple of the test machine's inventory parse on my test core server.

Event ID: 4100

Database exception: 4FB350~1.SCN, LDInv.dll

-2147467261

Invalid pointer

Update Table:Computer Column:SWLASTSCANDATE PK:,

What gives?

I've tried the stop inventory service - dbrepair - coredbutil - start inventory service, but this persists.

Examining the table (dbo.Computer SWLastScanDate column shows it is not a PK. Is it supposed to be?