I've been observing some odd behavior with this coin.  The network hash reported by the client jumps around wildly, and when it does the difficulty does as well.  I saw the difficulty go from over 24k down to 3.00 in a matter of seconds.

When that happens dozens of blocks come through in a second or two.

You might want to rethink your difficulty algorithm to keep the blocks coming through at a reasonable and expected pace.