to futher explain:

Before renaming song 01 to 08:
Song 01 is listed in this order
1- .CMP
2- .LSW
3- .MSP
4- .SEQ
5- .SQF
6- .TM

After renaming song 01 to 08
song 08 is listed in this order
1- .LSW
2- .SEQ
3- .SQF
4- .TM
5- .MSP
6- .CMP

When song 08 is added to a disk that has songs on it that were not renamed, only the renamed songs will not load. In my opinion, this is because, the order of the files is changed during the rename, and the 7000 can not decipher the difference.