Can anyone help a GPS rookie? Im trying to load maps from Mapsource Topo to my GPS. The maps are being transferred to the unit, but each map seems to overwrite the previous map (even though they do not overlap) I transferred a topo map of AEP to the unit, and everything was fine. Next, I transferred a map of the Little Miami River to the unit. The map of the LMR is fine, but the topo map of the AEP is no longer on the unit. Is this normal, or am I doing something wrong? Thanks!