we just got some RB3011UiAS-RM, and we have some problems with connecting the power connector.
The problem is that the power jack is too far from the enclosure, and the plug can not go inside enough to provide stable contact.
The only solution we could end up with is to use Mikrotik HighPower (1,6A) power supply (or regular 0,8A if you don't intend to use PoE out feature of RB3011), or drilling a wider hole on the enclosure. The power supply that comes with RB3011UiAS-RM is not compatible with the RB3011 itself.
This is a model from a new batch, I don't remember we had these problems with older models.