I took some time to look at the problem with the Jepessen NA data. It appears that none of the airports are shown on the map except airports that have control zones. The airports not shown are in the database. When you do nearest there are a dozen airports within 50 nm of CYXE, a couple of them within 15 nm and CRF5 is just outside the 5nm Class D zone around CYXE. I didn't think to compare the nearest list with the GPS495 but I suspect it's the same list. At any zoom level none of the airports (except as noted below) appear on the map. I checked the settings and the max zoom level for all types of airports is the default 30nm. I don't know if this means they will show up if the zoom is less than or greater than 30 nm but they don't show up at any zoom level. I also tried different zoom settings but still no joy.
One thing I did notice is that the airports with a control zone do show up on the map and on synthetic vision. See CYXE (Class D) and CYQW (Class E) on the screen shots below. The problem is that the round airport symbol blocks out the runway layout on the map. As a suggestion, it would be nice if the airport symbol disappeared at zoom levels where the actual runways can be distinguished.
None of the airports without a control zone show up on the map. On the screen shot below, I have a waypoint at CRF5. However CRF5 is in the database and CFS (Canadian Flight Supplement) and should show as an airport symbol on the map.
The class D (blue circle around CYXE) E (white circle around CYQW) and F (special use - red circle restricted area) zones are shown correctly on the map.
I think the database is complete (and correct) but there seems to be a problem of how it is displayed on the map.