unicode – now you see it, now you don't

FM 10, fully patched, on Windows 7

goal

use Unicode characters U+2192 and U+25C0

first approach

• set up character style !unicode using Courier New CE
• use F,U,P to insert Unicode characters – font set to Courier New CE

result

• U+2192 'rightwards arrow' displays correctly in the palette and in the document
• U+25C0 'black left-pointing triangle' displays correctly in the palette but just gives a feeble question-mark in the document
• checking via a different route tells me (unlike the F,U,P palette) that there is no U+25C0 'black left-pointing triangle' in Courier New CE

second approach

• modify character style !unicode to use Arial MS
• use F,U,P to check availability of both characters – font set to Arial MS

result

• U+2192 'rightwards arrow' displays correctly in the palette and in the document
• U+25C0 'black left-pointing triangle' displays correctly in the palette and in the document

question

what gives? less telegraphically, how come the palette and the document seem to have different ideas? It would save me, oh, minutes every eight or nine months if the palette gave a true indication of which fonts were going to play ball and which were going to play coy :-}