Ok...

[douglas]

Very bad strategy. You should always keep colonizing new systems until there are no unclaimed systems left, and you should do it quickly so as many of them are yours as possible. I think you may also be researching the other colony techs too soon. They are very expensive at 500000 research points each, and should not be researched until you can either do it quickly (I'd say 3-4 turns each max) or you have no important techs left to research that aren't also rather expensive (depends on the situation and the specific tech, but I'd say typically around 200000, though sensors and combat support 3 at 225000 are an exception).