Git on Mac, Windows and Linux, different status

Question

I have git installed in my MacBookPro, Windows 7 and a Linux(Slackware) PC

Mac:   git version 1.8.5.2 (Apple Git-48)
Win7:  git version 1.9.0.msysgit.0
Linux: git version 1.8.5.5 # I compiled it from source

And I have Dropbox installed in all of them to sync a project called, say 'projA'.

When I issue git status in projA, the results are different:

Mac:   clean
Win7:  some files are modified (# but the md5 of these files are all same in three machines.)
Linux: some files are deleted (#and they are really be deleted)

What maybe the problem? git? Dropbox?

Answer 1

Git repositories aren't really meant to be used that way. See this question:

Is it possible to host a bare Git repository using Dropbox, to share code?

It's safer to take Dropbox out of the equation and use a bare repo on one of your machines, or else use Github or one of its assorted competitors.