elgg mentions plugin not working for plaintext area?

I installed elgg mentions plugin and friend tagging and friend dropdown list both work inside a WISWIG editor, but when I type @ inside plain textarea like thewire form and hypeWall form, I can still tag a friend but the friends dropdown list doesn't show up. Anyone else has run into the same issue? What is the best way to solve this?

elgg mentions: https://github.com/Elgg/mentions