I dont' know what kinf of flux your using but I use a product called "Orange Crush" when trying to resolder connections on servos or drive boards. It's 100% water soluble.
Since I can't have any residue left behind, I wash the circuit boards off under warm to hot water to be sure it's all gone.
just a thought....
interesting Brock ... I should check manana. Ours really does smell like Pine Tar ... haha brings me back to my baseball days! we should perhaps open up our repertoire of flux's .... Thanks for the suggestion!