I had this happen in the past week.
If you put the following effect on a character.
Orange Prism Ioun Stone; NIFTAG: Channel; CL: 1d4-1
And you put in the tag "Channel" in your channel power it fails.
While trying to figure out why it was failing I clicked the cast button and got the following in chat:
[CAST] Channel Healing-30' (35' With Ring +1 To Select) + Tier Healing From Mantle [TAGS: channel]
The "channel" within "[TAGS: channel]" is lower case, even though it is uppercase in the spell.
So I tried changing the effect to have the tag being lower case and it now worked.
Something is making the tag within the spell lower case before it is compared to the tags within the IFTAG or NIFTAG effect.

