Missing chars when loading a font

Odd one this. The MtA font in the vtx_dt archive doesn't always load with all characters intact.

When loaded throug OpenDiskFont with the name MtA_US-ASCII.font it works.
Loaded any other way (even with the tag TA_CharSet,3) it always misses the following characters:
0xA4,0xA6,0xA8,0xB4,0xB8,0xBC,0xBD,0xBE

I did once manage to get it to load with the above replaced with that of 0xFF.

Easiest way to see the effect is to load up Typeface, go into the preferences, selection window and pick the font there, size 10 or 20 (might need to type it in).

Do the same again with MtA_US-ASCII and you see all the characters correctly.

I assume this is an odd charset conversion problem, but I don't get why specifying TA_CharSet,3 doesn't work when MtA_US-ASCII does.