I've come across this error a few times also. Sometimes I have ignored it, other times I have modified the metadata of the font file.
I am no expert on fonts, but as far as I can tell, if you check the internal metadata of the font file using something like FontForge or similar, you can check the internal naming.
I am not really sure which field is used, but looks like "Name for Humans" is the correct font name. Maybe one of the guru's could confirm?
But for this particular font, it seems to be full of errors according to the warnings in FontForge
-Edit-
I gave up on using smallcaps fonts. Instead I use, when necessary, fake smallcaps...
PHP Code:
.smallcaps {
font-size: 0.8em;
text-transform: uppercase;
}
I have noticed that the Libra2 does not respect the text-transform: uppercase anymore. Something changed in one of their updates.