Had the very same problem in my case it's due to the fact that you can apparently only see the 20 nearest caches to your location in the Geocache list, the others can be seen on the map list. Filters could be used to find the cache your after but I've not tried this.
A post helped me with this and the 20 cache limit, please see http://forums.Groundspeak.com/GC/index.php?showtopic=290694
Hope this helps.