Metformin (Glucophage) is one of the safest drugs around, but given that, there can be side effects, as with every drug. The incidence of lactic acidosis is down around 1 case per 10,000 patient years. It is very unlikely that you are having that type of reaction, and your symptoms don't point to it.
Metformin takes a few weeks to work, so it is not unusual that your BG is not as good yet. I'msurprised you were not started on metformin with then Actos added. The two drugs are substitutes for each other.