So far everyone who has responded to my initial post (4 or 5 replies) has
been a half elf. It seems that half elves have no problem and get
ultravision when they activate the DE illusion. So far no wood elf with a
Mask has responded. So if you are a wood elf with the Mask of Deception
please let me know if you are able to get ultravision when you activate the
illusion.

Last night I tried it again in Ogguk. Activated illusion and became blind
as a bat. This time I had Psalm of Cooling memmed instead of Psalm of
Warmth. While Cooling was up, I got ultravision. As soon as I stop playing
I became blind as a bat again. Faras posted that when he stopped playing
Cooling that he had to reactivate the illusion to get ultravision back.
This appears to be a bug but it doesn't affect me because I never had
ultravision in the first place.

Both the problem I have and the one Faras mentioned appear to be bugs so I
will post a message on the EQ board and Concert Hall to try and raise
support to get it fixed.

Galtin of E'ci