OK I tried the unmodified kernel and well crap (but a good thing) it's not Hijack or Left/Right Time Alignment, my apologies to mlord & Christian for thinking it was but had good reason. I had no such thumps for a year and even had none happen with Hijack I update my empeg w/Hijack about as often as mlord posts them (I miss a few) other than that I haven't messed with the software. The weird thing is I've had v2.b11 for quite awhile w/o the thumps well since b11 came out to just a few days ago w/o thumps.
I guess I'm going to have to go dash digging for a loose wire or connection, if it isn't the b11 bug.