Can't select device in a Group condition

Hi,

I would like to use the EasyTrigger's "A Device Strings value" "Contains" a certain string in a Group Condition.

The problem is that as soon as I select the Device from the Device drop down, it's cleared out with the "(Select a device)" text.
The same is also true for the "string contains" text box. When I click submit, the text is not saved.

I'm using plug in version 3.0.0.27.

What can the problem be?

thanks
Mats