Again, thanks a ton DiapDealer.
Yeah, just found out today about AZW and mobi being same with only file extension difference. Silly Amazon.
Of course, you are right about the dupe files and your suggestion makes perfect sense. Will try ASAP.
For sure, I need to dig much much deeper into the awesome calibre. It is terrific that not only is Mr. Goyal active here, but that there is a good synergy between him and mobileread.
cheers and thanks for the tips!
-les