My nuvi 1490t had a problem after updating to software v. 4.90 - the traffic icon was not shown anymore. Per instructions from Garmin Support, I reseted the GTM FM Table and all works OK.
Nevertheless, even when I receive good and relevant traffic information, if I go to Tools/Settings/Traffic a message pops-up informing me that:
"The traffic subscription has not been activated. Activation occurs automatically when your unit acquires satellites and receives traffic signal data."
This seems to be a bug in nuvi 1490t software version 4.90