I feel that the ops in the Philapines, Thialand, or India tend to get flagged quite often. I avoid those places for that reason and have recieved all but one of my orders with no problems.

Is your letter a standard customs letter? That is what it sounds like. It usually will tell you what is being detained and why. If anything bad was going to come of this, I think you would have been visited. So I would just chill and toss the letter like the rest of them.