Mb is megabits, MB is megabytes.
I haven’t checked, but I suspect the same is occurring for Kb and KB.
What is really being returned is now called MiB (mibibytes). We have the marketing departments in the hard drive industry to thank for the bastardization of MB (by calling 1MB = 1,000,000 bytes instead of 2^20). But I won’t hassle anyone for failing to use MiB.
Thanks for the report, I have checked in a fix for the next update.