Hitting return to rename a file is the standard by Mac OS X.  One thing Apple emphasizes is consistency across the UI.. and personally I'd find it rather distracting to have to use a different hotkey to rename than OS X uses and most of my other apps use.

Just my $0.02.

[without]

Please update me with the situation on this. Thanks

I'm fairly certain I've run into this before.  It typically happened when I'll update a file locally, and attempt to upload the file without refreshing the local view first.  Since upgrading to v1.1.5 I haven't had this issue at all..