GPS antenna lag?

[cktsi]

I installed an RNS 510 unit 12 months ago. The unit tracked my position fine. However about 2 weeks ago the inidicated position now lags behind the actual position.

I have not done any mods to the unit and installed it stock myself. Purchased it from ebay from the lithuanian ebay seller.

I have removed the unit and checked to see if the antenna has slipped from the place i installed it (which was above the central air vent) and it is still there.

Any thoughts? Should i try replacing the antenna? Has one of the GPS satellites been knocked out of positions? :p any solar flares i should know about? :p

Any suggestions appreciated.

[Transporter]

Some say that the location above the glovebox is better. Try to leave the antenaa on the dash for testing to see if that improves.
There are some threads with the similar topic, so maybe look at them to see what was the others solution for the problem.

[Lindsay]

Mine dropped out for a little while and I could not work out what it was. Upon further investigation I found that the cord had pinched itself in between some plastic trim and it was enough to lose GPS signal