I have a netbook, running slow. Should i upgrade the RAM? Or is it the processor the problem?

I don't exactly expect blazing fast speeds, it's a netbook after all. I actually run Ubuntu on it since Windows is a bit of a memory hog. But I'm wondering if upgrading the RAM from 1GB to 2GB will improve speed, or if the computer is too limited by the 1.66GHz processor? When I say "running slow" I mean things like sometimes I'm typing faster than the computer is willing to display the letters I type. Or the computer takes an eternity to open up a program. The exact model is an ASUS Eee PC 1018PB-BK801 with an Intel N450.