You said it veetwo...
NDB's, either in en route nav or in approach situations can sometimes be dangerously inaccurate, especially if subjected to shoreline, night time or mountain effects. Tracking to an NDB without some kind of DME (or GPS readout) fix can also make life tough, seeing that the needle gets unreliable within about 2nm of the beacon.
There is a particular airport on the west coast of British Columbia which has a reputation for being a not very nice place to fly the approach into, particularly at night near mins. IMHO, NDB's should be outlawed in some locations due to their flaws. Its all good and dandy in nice flat, no terrain or shoreline locations, but try it elsewhere and it can give you that sickening feeling as you arrive at your MDA and the needle is jumping all over the place...
