I've got a Sportster in my vehicle thats about 3 yrs old, no problems with it at all until a few weeks ago. It is now constantly cutting in and out and displaying the dreaded "Aquiring Signal" message! On some occasions the signal will be lost up to 70% of the time I'm in the car. Incredibly annoying to say the least! Is it my radio, my antenna, or issues with Sirius? Is this common with units that become "old"? Thanks in advance for any help provided.