[Dx4win] Merging Logs

[WO8L at aol.com]

Hi,
 
Version 6.03 seems to include duplicate contacts when merging logs using  the 
DX4WIN log utility.  Any advice on this?
 
I can't find a pattern to it.  At first, I thought it might be that  some 
QSOs with the "Y" for QSL didn't transfer correctly.  But there's  something more 
to it than that.
 
Basically, I keep a log from the year 2000-2004 and a log from  1967-2004.  
When one merges the recent log into the "master" log, there are  tons of 
duplicates.  
 
Suggestions?
 
73s,
 
Rick