Code:
<Page Location="135,0" Name="BestowalOfVitaePage" ScrollExtent="27,27" Size="27,27">
<Button LocalTooltip="reactive heal" Name="BestowalOfVitaeButton" OnPress="target_none
target_self
useability Spell" Spell="Supplicant's Prayer" Opacity="0.000" ScrollExtent="27,27" Size="27,27"></Button>
<Icon IconRect="209,0,252,39" IconResource="images/icons/icon_ss6.dds" Name="BestowalOfVitaeIcon" ScrollExtent="27,27" Size="27,27" TreatAsButton="true"/>
</Page>
Replaced useability Supplicant's Prayer with useability Spell and add a Property names Spell (Spell="Supplicant's Prayer"). This is the only way I've been able to reliable get the game to use spells with ' in them. It is also how the click to cure/cast works in Henchman.