The timings don't really matter if you are not overclocking, and if you are, the 1gb sticks don't overclock well anyway. It basically is how long it takes to go for cas, ras to cas is the next one, than something else to do with RAS percentage, and than active to precharge. The lower the better. But as I said, it doesn't really matter unless you overclock.
For the downclocking, what CPU do you have?
If you have a older AMD 64 - pre Venice, than it will downclock the ram, if this happens just set the cpu and ram to a 1:1 ratio, or if it is CPU/** set that number to your multiplier's number.