API call Actions.getPageUrls date range error (no replies)

I have a problem with the API call of Actions.getPageUrls. When I call:

http://myurl.com/index.php?token_auth=...&idSite=27&module=API&format=JSON&method=Actions.getPageUrls&flat=1&filter_limit=1000&idSubtable=299&period=range&date=2013-09-05,2013-09-10

I get this error:

{"result":"error", "message":"La date '2013-09-05' ne correspond pas au format suivant :  'lastN', 'previousN', 'YYYY-MM-DD,YYYY-MM-DD'."}

But with other valid values of idSubtable, for example idSubtable=303 I get the expected result:

[{"label":"492","nb_visits":1,"nb_hits":1,"sum_time_spent":30,"sum_daily_nb_uniq_visitors":1,"url":"http:\/\/myurl.com\/\/entity\/103\/view_video\/492"}]

And for invalid values of idSubtable, for example idSubtable=30399, I also get the expected empty result:

[]

Any idea? Is it a bug in Piwik?