Piwik v1.12 with almost 800 sites.

The following API request

module=API&token_auth=OURTOKEN&method=UserSettings.getMobileVsDesktop&period=month&date=previous1&idSite=all

results in this error:

Fatal error: Call to undefined method Piwik_DataTable_Array::getRowFromLabel() in /var/www/html/piwik/plugins/UserSettings/API.php on line 108

It is strange because the following request is successful, which should be the same report as above:

module=API&token_auth=OURTOKEN&method=UserSettings.getMobileVsDesktop&period=month&date=2013-05&idSite=all

And I get a successful result with period=month&date=previous1 if idSite != all:

module=API&token_auth=OURTOKEN&method=UserSettings.getMobileVsDesktop&period=month&date=previous1&idSite=846

This seems like a bug with the previous keyword, because specifying period=month&date=2013-05 should be the same report as period=month&date=previous1, right? And it seems like it may be specific to getMobileVsDesktop, as none of my other monthly reports have trouble using the previous1 keyword.