"The standard search results are incomplete because the property indexes are being created. Complete search results will be available once the file properties are fully indexed"
This can happen for two reasons.
1) The administrator has recently initiated a "Rebuild Search Indexes" from the ADMS Console. In this case, in the Tools>Server Tasks Pull down menu, The "on-demand" "Search indexing" task will be running.
2) One or more users have recently checked in a large number of files that are still waiting to be indexed. The time it takes to process this will depend on the number of files to be processed, the current workload of the server itself and the hardware resources it has available.