Read from this discussion thread and my current experience (annoyed by a USB drive), a USB drive formatted to exFAT in Mac OS X is unable to write in Windows 7. However, a disk formatted with exFAT in Windows 7 can be read & written in Mac OS X.
Why is this issue happen? Is the exFAT standard used in Mac different than in Windows 7? I seek for a technical reason for this issue.
Note: I'm not asking for read-write solution (I can make an exFAT disk in Windows 7)