Only listing for uefa euro games on ART i can find is uefa super cup on 26-8-05...AFAIK ART don't have any rights to show Champions League matches.
As far as ART cards, mine seems to be working fine at the moment
spoke to a dealer yesterday and he guarntees the new cards will last 6 months, he said they clear for 7 days, in the 7 days you get the numbers send them to him and he sorts out the rest...so its seems to be ok? but i can't really try it out as i've just actived my 6 month card so it will be 6 months before i could try a new card out...fingers crossed i'm going to keep an eye on his feedback to see if he can get the cards acctivated for the full 6 months..
P.S H ave you looked into the alternatives to ART? ...TPS, DIGITAL ALB...etc?