Hi! I’m encountering a problem where certain kerning groups don’t seem to be exporting.

I’ve got groups set up eg. @UC_VW & @A, with a kerning values set like:
@A @UC_VW -104
@UC_VW @A -100
(BTW,is there a standardised naming format for kerning classes?)
Now when I generate my font, kerning works for the first set… but not the second. What am I missing?

Here’s an abridged version of kerning.plist from the UFO, there appear to be no individually kerned conflicts or even groups that double up. When I do kern the pairs glyph-by-glyph it works as expected, but groups would make things a lot easier…
…
<key>@A</key>
<dict>
<key>@UC_VW</key>
<integer>-104</integer>
</dict>
<key>@UC_VW</key>
<dict>
<key>@A</key>
<integer>-100</integer>
</dict>
…

I don’t have Metrics Machine, can’t afford it right now :(

Any suggestions would be appreciated. Ta!

Andrew