On Fri, 15 Feb 2008 20:30:13 -0000, Lew 1 wrote:

Actually, while I am here, can someone please explain to me why my Oyster
card regularly opens gates, but then flashes up "Seek Assistance" while I am
crossing through? If there is a problem, why does it open the gates? What
does it all mean?!

It happens if you hold your Oyster near the reader a fraction longer
than necessary. The reader reads the card, completes the transaction,
and opens the gates. It then reads the card a second time, and this
time rejects it as a double pass-in (or out), displaying the "seek
assistance" message.