So I have this macro on my DK:

#showtooltip
/cast Mind Freeze
/cast Strangulate

Problem is it ALWAYS casts strangulate, even if the mob is right in front of me, none of my runes are on cooldown, i have plenty of runic power, etc, strangulate still gets cast.

I'm not sure if this is because mind freeze doesn't trigger the global cooldown, maybe its casting both? Any ideas on this? Is my only solution to put them on separate keys?