UCU fees don't add up

The time has come to pay University and College Union subscriptions for 2007 08. My subscription request outlines, without explanation, different rates for former Association of University Teachers members and those who were formerly in Natfhe. For those earning more than £40,000, former AUT members pay £13.96 per month and former Natfhe members, £14.54. What does this tell us about the workings of our so-called union?

Hazel Dewart
Professor of psychology
Westminster University