Very basic CAN database problem (3.2.2) "end bit of signal is out of message length"

[etuer]

I create a new message, 8 bytes long, in the CAN dbf editor.
The first "signal" should be starting at bit 0, 16 bits long, unsigned int, motorola type.

It doesn't allow it! The error is "end bit of signal is out of message length"
It will allow if it's Intel format. Or if the signal length is reduced to 8 bits.

Then the next signal, which should be starting at bit 16 (or byte 2, bit 0), in fact is sent starting at byte 1.

Am I misunderstanding something basic, or does this just not work?