Hey you hordie jerks :P,
Mine does the same exact thing but i found a way around it. If you have 5 stacks of 10 in ur backpack and try to post 15 stacks of 3, it ****s it allll up as you know. BUT if you break em down into stacks of 3 and make sure they will be the first stacks the add-on "sees" in in your bag(I.E: the first stacks of that item starting from backpack slot #1), it will post how its supposed to, make sense? Obvi the stack sizes dont matter, just make em whatever ur trying to post. Oh and this led to me getting this add-on "Fence" which has nifty hotkeys for breaking down stacks, highly recommended
Can we get a response from Warmane here as to why this is happening? I have never seen this issue on other servers. It's an incredibly frustrating problem to deal with when trying to make gold for your epic flying before gold squish.