Not all test cases are importing from Excel to QC

I've imported multiple times 120 test cases to QC and yet it only took 100 of them.  When I did 100 test cases, I got 79 copied.  When I did the other 20, only 18 came over.  Does anyone know why this is happening?  What can I do about it?  Is there a limit to the folder?  I broke it up into 2 folders since the 120 test cases were always coming in at 100. 

Thanks!