Your MCH is the P43 and your ICH is a ICH10, both good parts.
The Intel MCH or Northbridge chips tend to run rather warm relative to other components. They are capable of tolerating a high temperature, the actual maximum temperature specified for the P43 is 103 C. The ICH10 has a maximum temperature of about 100 C, I don't recall the exact value but it is +/- two or three degrees from that.
You can read about the P43 in the following link, the temperature specification is in section 2.3.3:
The temperatures you mentioned are normal for these chips. If you can add more fans to your PC case, or even put a small fan on the heat sinks they may run a little cooler. Those chips must have a heat sink on them, do not remove it permanently.
On some Intel mother boards, the temperature monitoring of the MCH will not display a temperature below a certain value. On my DG45ID mother board, the BIOS and other temperature monitoring software always shows a temperature of 66 C, which is the minimum temperature the system will indicate. Your mother board may be operating the same way. You may be able to find that information in the Technical Specifications for your mother board.
It's good that you are checking these things, but you have nothing to worry about.