[adjuvantjfoster]

I have the BU-353 SIRFIII Water Proof USG GPS Receiver and MacENC software for navigation.

Is this WAAS satllite change a GPS firmware or a software issue? What if anything might I do if needed?

From the Panbo.com blog site: WAAS Critical Update Information

On July 31, 2007, the FAA will decommission WAAS satellites 122 and 134, leaving satellites 135 and 138 for WAAS differential corrections in North America.

In all Hemisphere GPS receivers with a WAAS application, shipped before April 2007, the WAAS firmware does not recognize satellites 135 and 138 when performing an auto-search. In order to continue receiving WAAS differential corrections after the July 31, 2007 cutoff date, Hemisphere GPS receivers must have updated WAAS firmware loaded onto their systems or have satellites 135 and 138 manually selected through a terminal communication program.

John

Things change.
Try to cope.

[GPSNavX]

As you found this was a better question for the manufacturer of the GPS. It would not be a GPSNavX or MacENC issue..

http://www.usglobalsat.com/forum/topic.asp?TOPIC_ID=825