Cremate Knockup Bug?

[Masterfoos]

Was brought to my attention that the persons character was now being affected by the .75 knockup created by cremate. I logged on 3 different farmers 2 Brutes and 1 Tanker and tried the map out. Sure enough, I was getting knocked down severely on my tanker farmer FA/FM. My Spines/FA/ brute I noticed a few knockdowns, my BA/FA brute I didn't notice any knockdowns. All 3 toon have +1 knockback protection from TP, I then slotted my tanker with karma +4 kb prot for a total of +5. The combat log was still saying cremate has knocked me off my feet, but my character wasn't actually getting knocked down any longer. The combat log says the same thing for the BA/Fire brute but he's not getting knocked down either and he's still at +1 kb prot. Anyone else noticing this issue? The mobs in this farm are using FM/SR powersets and were at +4. 

[csr]

Due to the Purple Patch +4 level foes will have their KU increased to greater than 1 against you.  So the only odd thing you reported is your BA/FA Brute not being KUed.  Did you verify the 1 KB Prot in Combat Attributes to make sure that's all he has?

[Masterfoos]

I did, all 3 only had 1.0 kb protection at the time of testing. I did notice the BA/FA Brute get KUed after posting, but it was once or twice out of 10 maps. I thank you for your time to answer and explain. Maths in this game don't tickle my feel goods unfortunately.