Moving files work usually, but fails when some umlaute are in the file name

test set:
'with ä.test' 'with blank.test' 'with ß.test' 'with ".test' "with '.test"

protocol from syslog (relevant lines only):

Jan 20 10:26:51 InaUbuntu grive-sync.sh[50561]: Syncing 'google-drive'...
Jan 20 10:27:04 InaUbuntu grive-sync.sh[50569]: sync "google-drive/test folder/with '.test" moved to "google-drive/with '.test". moving remote
Jan 20 10:27:04 InaUbuntu grive-sync.sh[50569]: sync "google-drive/test folder/with blank.test" moved to "google-drive/with blank.test". moving remote
Jan 20 10:27:04 InaUbuntu grive-sync.sh[50569]: sync "google-drive/test folder/with &".test" deleted in local. deleting remote
Jan 20 10:27:04 InaUbuntu grive-sync.sh[50569]: sync "google-drive/test folder/with ß.test" deleted in local. deleting remote
Jan 20 10:27:04 InaUbuntu grive-sync.sh[50569]: sync "google-drive/test folder/with ä.test" deleted in local. deleting remote
Jan 20 10:27:04 InaUbuntu grive-sync.sh[50569]: sync "google-drive/test folder/with ß.test" moved to "google-drive/with ß.test". moving remote
Jan 20 10:27:04 InaUbuntu grive-sync.sh[50569]: sync "google-drive/test folder/with &".test" moved to "google-drive/with &".test". moving remote
Jan 20 10:27:04 InaUbuntu grive-sync.sh[50569]: sync "google-drive/test folder/with ä.test" moved to "google-drive/with ä.test". moving remote
Jan 20 10:27:04 InaUbuntu grive-sync.sh[50561]: Sync of 'google-drive' done.
Jan 20 10:30:01 InaUbuntu grive-sync.sh[51051]: Syncing 'google-drive'...
Jan 20 10:30:08 InaUbuntu grive-sync.sh[51074]: Retriggered google drive sync ('google-drive')
Jan 20 10:30:09 InaUbuntu grive-sync.sh[51059]: sync "google-drive/with ß.test" deleted in remote. deleting local
Jan 20 10:30:09 InaUbuntu grive-sync.sh[51059]: sync "google-drive/with &".test" deleted in remote. deleting local
Jan 20 10:30:09 InaUbuntu grive-sync.sh[51059]: sync "google-drive/with ä.test" deleted in remote. deleting local

As I understand the moving remote does not work, therefore the file is deleted in the time triggered sync. As the moving first appears to work on the local files system and the deletion occurs later there is some considerable risk of losing data.