Say What? LaborDtl Table has LaborHedSeq = 0 records

I see quite a few LaborDtl records that have a zero for the field LaborHedSeq.
The majority appear to be related to either adjustments, QC trans or job splits.

I am trying to upgrade from V9 to V10 and my migration is failing on the LaborDtl table. 


In trying to figure out the problem I saw the log files pointing to EarnedHrs only allowing 6 digits.


So I used ODBC to search the LaborDtl Table and found 11 records that have EarnedHrs greater than 9999 or less than -9999.


I also see that the first 5 records of my list have the LaborDtl.LaborHedSeq as zero (0). 


 How is that possible?  I thought each LaborDtl.LaborDtlSeq had to have a LaborDtl.LaborHedSeq for the record to be valid?


When I did a search for just records with LaborHedSeq = 0 I got 1800 records.  A small number since we have millions of records.


Anyone have any thoughts?


Thanks,

DaveO