Array to string conversion for CustomPress when upgrading to Jetpack 3.8

Dear Support,

I upgraded to the latest version of Jetpack today (v3.8.0).

There was a message as part of the upgrade process - "Notice: Array to string conversion in ........./plugins/custompress/core/core.php on line 81.

Is this something I should be worried about? I would like to start using CustomPress a lot more but would be apprehensive if general plugin upgrades will start to prove problematic.

Thanks in advance,
Will