Hi Chapman,
You're a little bit under minimum requirements with that setup. I'm not terribly familiar with Macs, but having dual 1gHZ processors unfortunately doesn't add up to having a 2gHZ processor. It would be roughly the equivalent of 1.6 gHZ to 1.8 gHZ (ballpark) and that's still just a bit under the Pentium-4 2.0 gHZ min requirement. There are other factors too, such as ram bus frequency that can slow down the excecution of your PC as well. If your ram can't keep up with the speed at which your processor operates then that can slow the entire system down. It's not always about the pure numbers and processors can often be slowed down by the equipment that surrounds them (ram bus frequency, CPU cache and other factors).
For example about a year ago this system I'm on had a 3.0 gHZ Celeron processor, which going straight by the numbers should've meant I had no issues, but Celerons are the "cheap" processors and my performance was really suffering. I "upgraded" my CPU to a 2.4 gHZ P4 processor and though by the numbers it may look like a downgrade, the Pentium was way more efficient and in the end operated faster. It's kinda like comparing a Toyota Corolla to a Ferrari. Both will go 100mph, but the Ferrari does it with a whole lot more efficiency and has some horsepower to spare.
Remember, the specs listed are absolute minimum requirements. If you don't meet them you will experience general game slowdown across all areas (not just the meter). Skipping animations, extended loading & meter issues are all a product of low frame rates, which is likely because your processor(s) is working overtime to try and keep up with the demands and the graphical hardware acceleration is suffering as a result.