Hi, I don't know what all is included in the gps v3.3 demo package which I gather you downloaded, but you need to use maps from v3.1 or later and also you need to use the .poi files which are new with v3.3 as the older ones will not work correctly if at all.
I'd contact Sendero if I were you to be sure you have files of the proper versions to work with what you have. If you get the "acquiring fix" message, it's most likely your gps is "seeing" the receiver. But, if you haven't used the receiver for a very long time, it can really take quite a while for the receiver to get a fix. You also need to be sure you are in a location where satellite signals will be strong as this is quite important with the first time you attempt to do a fix if you haven't used the receiver in several days or weeks. Again, I'd contact Sendero directly on this one. Don
