same here, should be 100MHz, goes as low as 50 and higher than 110, causing CPU clocks incorrect reading. happens more frequently during heavy load or gaming, but noticed even in idle or light usage e.g. browsing
I have posted build 4257 to resolve the problem with crashing on Intel GPUs with current drivers in the above mentioned thread.
This should also resolve your problem with bus clock.
Please let me know if all is well now.