The memory controller in your 3200+ chip determines the RAM frequency by dividing the CPU frequency by an integer. So, if your CPU frequency is 2000 MHz, the divider might be 10, which gives you a ram frequency of 200 MHz.
Now, when you speed up the processor, it recognizes that your RAM isn't qualified to run at 2350/10 = 235 MHz, so it increases the value of the divider. 11 would still be too high: 2350/11 = 214 MHz, so the multiplier increases to 12: 2350/12 = 196 MHz.
If the original RAM frequency was 200 MHz, you're not paying too great a penalty for running it at 196 MHz (2%) compared to the increase in CPU frequency (17.5%), so long as your timings are the same.