I just noticed you are in the UK, TA is something us US folk generally don't use. From the 2.00 release notes:

Mk.2 & Mk.2A owners note: the powered antenna line will always be active
while TA is switched on, so that the tuner can scan for the appropriate
RDS information.
_________________________
-Rob Riccardelli
80GB 16MB MK2 090000736