I think the gold drop was a result of margin calls on the CME for silver.
Frankly I think the recent silver upmove from $18 was a complete and utter bubble, the chasing of easy money in contracts, and it's now in the process of popping.
There are still good fundamentals for PMs, but we'll see a small correction.
The commodity exchanges are also in the process of upping all their margin reqs: gold will be next, as well as a lot of Agri commodities.
It's always a good idea to pop a bubble before it gets too large.
Just my opinion, YMMV, haven't researched it yet because frankly after Tuesday's bubble pop, I'm bored with subsequent PM moves.