Report Sums Not Consistent

[farmboyjohn]

I have set up a database to track maintenance activity applied to different
properties. In one of my reports, each maintenance employee should show a
separate SUM of the hours applied to EACH property for a given span of time.

When I run the report, if an employee has multiple entries against the same
property in the source "time log table" then the TOTAL gets printed as it
should. However, if there is ONLY ONE entry for a particular property, then
the total MAY OR MAY NOT print out. If I run the report multiple times, the
result is consistent.

I can email a .pdf of the design view of the report if helpful