drag and drop interface to bond - does not scroll to the network

Hi,

I have a couple of Dell R900s that I am trying to get setup in a RHEV cluster.

This is my first production cluster and I've run into a strange one. I am trying to bond two network interfaces for the mgmt network, but these boxes have loads of network interfaces and I am trying to drag and drop eth0 quite far down the list to the network with the first interface in it... but when I grab the interface and drag it, the window does not scroll down, and I can't drop it on the right network. As I want to keep one interface on each board for redundancy, I can't remove any to reduce the list...

I am using rhevm 3.4... any ideas? I'm using firefox - maybe another browser?