DevicesDetection: Warning - array_key_exists() (1 reply)

Matt, et al: I have been getting this since warning message since upgrading from 2.10.0 to 2.11.0-b4 (and it persists through the upgrade to "official" 2.11.0):

WARNING DevicesDetection[2015-02-19 11:26:20] [3d3fb] /path/to/piwik/plugins/DevicesDetection/functions.php(63): Warning - array_key_exists() [<a href='function.array-key-exists'>function.array-key-exists</a>]: The first argument should be either a string or an integer - Piwik 2.11.0 - Please report this message in the Piwik forums: [forum.piwik.org] (please do a search first as it might have been reported already)

I did a search here but did not find it reported.

Thanks