Is this dependent on internet speed? Anyone know how to make it happen more often? Also, how can you catch this?
Internet speed is irrelevant, unless you count basic internet speeds to even access neopets as the absolute minimum.
You can't "make" it happen more happen as much as you'd like to think you can. Sending multiple requests by clicking buttons that sends info to the neopets server that prompts it to respond (which is the basis for any duping in Neopets) depends on server side lag, not your internet speed. However there are ways to increase the chance of duping server requests at any given time by the speed at which you send requests to the neopets server and being cognitive of lag spikes.
Catch what? Chlamydia? The leader of ISIS? Be more specific.
When you say training school, do you mean on the completion of the quests?
Take it as you will, but I suggest thinking to yourself: how else would the info I just said make sense?
Soooo can we dupe items again?
Nope.
TNT prioritized eliminating the game-breaking glitches and left the minor ones untouched most likely because of the lack of resources.