Units in CAS mode?

[Ollie]

Hey, I've tried learning how to use the prime unit system properly but failed miserably.
I checked the user guide .pdf and they had an example:

Well, I tried this with the emulator and here's what happened:

Uhh, that's a bit weird, how about in the normal non-cas mode:

Seems to work fine, but wait! This works in cas mode:

That's a bit odd, isn't it?

Alright, well next up unit conversion.
CAS:

Fails, how about the non-cas mode?

Doesn't make any sense.

MKSA?

NOPE, works fine in normal non-cas though.
Same with USIMPLIFY..

So, why can I not use units properly in cas mode?