+1 for this as well. However, it is pretty specific that this is with regard to automatic discounts. I can't even seem to stack discounts when they are all manual. Is this an issue I'm having or does the limitation also apply to manual discounts? If so, these limitations should not be so specific as this is misleading.
Editing to say that I've learned it does apply to manual and automatic. The verbiage on the discount page IS misleading, though. "Can't combine with other automatic discounts" implies that manual discounts can be combined.