(this is on ftb unleashed, but i dont think that matters)

right, so im minding my own business in my new home (in a cave) putting my valubles into a chest when all of a sudden a creeper drops out of a hole in the roof and blows my chest up, panicking i put myself into creative mode, only to find that once my inventory was full i was still picking up the items, i have now emptied my inventory and the items i picked up when my inventory was full are nowhere to be seen?, i have checked the creative inventory and im now very puzzled.

Please help, and thanks in advance