searching for user details

Hi,
I'm setting up a site for my archery club, public site set up in WordPress, using Vanilla as members area - and everyone loves it ;)
(quick screenshot: http://screencast.com/t/MmZkZjYw )

I've got everyone signing up at the moment - using the Custom Info in their account settings to specify their bowtype, and further details about their archery kit.
Now I've had a request come through - the ability to search user by bowtype, for example. I thought the built-in search function should be fine for this as you can choose to search users. But it does not work, I've tried various different searches myself, using advanced search - but nothing comes up at all... :'(
The search function is fine - all working well for user names etc....

I'm wondering whether the custom info does not get searched at all? Or whether there is anything I can do about it....?
any thoughts on this would be much appreciated :)

prisca

anyone?