How strange.
May be a better method would be to format it FAT and then every machine could read it. Not as efficient but if the purpose is purely to transfer files between Mac and Windows, it will work.

Aren't thumbdrives formatted in that way?

The Mac can read a FAT32 disk but has problems with the NTFS format.

Of course, the old standy of 6ft. of Cat5 works too.

P