Selector working in one place and not another

[Paragon]

Okay, in my usual attempt to fiddle with the 4e files, I'm trying to make the fifth level Scholar Theme option at least provide a choice between the two things its supposed to be doing. As an example of something (working) that allows you to choose between two other "things" this is the chunk of code that allows the Dragonborn characters to pick between two powers:

<thing id="fXDRP" name="Dragonborn Racial Power" description="When you select dragonborn as your character&apos;s race, choose one of the following powers. Your dragonborn character gains that power." compset="RaceFeat">
    <fieldval field="usrCandid1" value="thingid.pRacDraBre | thingid.pRacDragon"/>
    <tag group="Hide" tag="Special" name="Special" abbrev="Special"/>
    </thing>

This is the chunk of code I was experimenting with with Scholar to select from two features, and the two features involved:

<thing id="fXSchl5" name="Scholar Leve l  5 Feature" description="Choose training in one new skill and one new language. The skill you choose must be Arcana, Dungeoneering, History, Nature, or Religion; if you already have training in all of these skills, you instead gain a +2 bonus to skill checks with one of those skills. The language you choose must be Draconic, Dwarven, or Elven; if you already know all three, choose one language from those listed in the Rules Compendium (page 69) or Player&apos;s Handbook (page 25)." compset="ThemeFeat">
    <fieldval field="usrCandid1" value="thingid.fXSchl5a | thingid.fXSchl5b"/>
    <tag group="ReqLevel" tag="5" name="5" abbrev="5"/>
    <bootstrap thing="fXSchl5c"></bootstrap>
    </thing>
    
    <thing id="fXSchl5a" name="Scholar 5  Bonus Skill" description="Choose one skill from Arcana, Dungeoneering, History or Religion." compset="ThemeFeat">
    <fieldval field="usrCandid1" value="thingid.skArcana| thingid.skDungeon|thingid.skHistory|thingid.skNature|thingid.skReligion"/>
    </thing>
    
  <thing id="fXSchl5b" name="Scholar  5 Skill Bonus" description="Gain a +2 bonus to Arcana, Dungeoneering, History, Nature or Religion" compset="ThemeFeat">
    <fieldval field="usrCandid1" value="thingid.fSkBArc2 | thingid.fSkBDun2 | thingid.fSkBHis2 | thingid.fSkBNat2 | thingid.fSkBrel2"/>
    </thing>

The Dragonborn selector works. However, when I try to use mine with the theme, while a selector pulldown comes up, when clicked on, it simply indicates "Nothing to select from."

Any ideas? Some kind of a timing problem?