Since this has worked for you in previous versions, lets do some basic things to make sure you don’t have some old configuration files that don’t like the new version of BitComet.
In response to your recommendation for a uninstall/reinstall…
I broke my system volume RAID mirror, again confirmed the scheduler uncontrolled rate behaviour, uninstalled, rmdir/s D:\program files\bitcomet, reinstalled.
Again I quickly observed that setting all scheduler rates something like 10KBps, shortly after starting a task the rates were significantly higher, for example 45 down 90 up.
I repeated the uninstall and reinstall starting from C: rather than D: with similar results.
From your description and fishing about I observe that the bitcomet.exe is not requestedExecutionLevel level=asInvoker, relying on settings in the installed directory file bitcomet.xml. However I am using a pre Vista system and therefore the Vista virtualization hazards don’t arise.
Something else:
During this process I was able to confirm another issue, which perhaps doesn’t deserve another forum thread.
Starting with all the scheduler rate settings unlimited, if I assign “High speed download limit” value 4, I then observe the new element in bitcomet.xml: <SchedulerDownloadLimitLow>4096</SchedulerDownloadLimitLow>.
Then after opening the scheduler dialog again, I find instead “Low speed download limit” has value 4.
A similar muddle is observed when assigning to “High speed upload limit” with the value 6, turning up the element <SchedulerUpdateLimitLow>6144</SchedulerUpdateLimitLow>, then upon scheduler dialog reopen the value shows in field “Low speed upload limit”.