Windows 7: Certain Compact Flash cards while transferring eject

Very strange issue with certain compact flash cards being transferred to computer. I have 4 Lexar USB 3.0 CF card readers attached to a HighPoint 4 port USB 3.0 card. When transferring a 1000X CF card I have no problems. Certain cards like a 600X card will transfer fine but when it gets down to 10 files remaining out of over 600 it ejects and then an error pops up saying can't read from volume. In the meantime the card remounts!!! If I hit continue the card dismounts again only to remount. Very bizarre that it always does it at the very last 10 files. I haven't been able to narrow it down to which cards or types just yet. Kinda just started happening.
I do have Diskkeeper installed and also Nero. Read some random stuff about Nero messing with certain volumes.

Any ideas or thoughts? Things I can check or investigate?



Thanks,
Toby

Small update....
I notice that it is not the last 10 files but literally the last file!!!! It just throws up the error message with 10 remaining but if I click "Skip" it finishes the other 9 leaving out the last file only. Bizarre.
I am going to try to format the cards on my computer rather than in camera and see if the problem persists.
I will post an update in case anyone cares or has a similar problem down the line.

Toby

Okay just a quick update for anyone that cares or maybe runs into the same problem. I wasn't able to find any definitive answer online with a quick google search but I seemed to fix my problem by formatting all the cards on my home computer before using in my three cameras. After doing the format and filling the card with images from a wedding, when I got home to transfer all the images, no error or dismounting at all.
Hope this helps someone.

Toby