Border Select mode doesn't seem to be working in 2.53

I have searched for this problem but can’t find an answer.
Using Blender 2.53 beta and working through the examples in the “Essential Guide to learning Blender 2.6”. This was working earlier but has now stopped, I guess I must have toggled something on or off. So I closed Blender, started new session, reset by “Load Factory Settings”, Press “A” to select everything then delete it. Shift+ “A” add a cylinder, switch off end caps. Go to front view, Ctrl + Tab to select “Edge select”, Click “B” to select top edge of cylinder (in order to scale it). MMB rectangle around the top edge, but nothing highlights. Select “B” again and try to select vertical edges using MMB again, nothing selects.
What did I break? :wink:
<edit>Oops forgot to say yes I am in Edit mode!</edit>

Try LMB instead of MMB when selecting. MMB deselects

Thanks Richard! I obviously had a severe case of “brain fade” :wink: