Only one star with a PPV percentage scale built into his contract has ever fought on a European UFC PPV show. His name is BJ Penn, and the show (UFC 80) did 225,000 buys. Given the very small bonus he got, it's no surprise that he doesn't have interest in participating in a tape delay PPV show from Germany.
Anderson Silva was originally pencilled in to fight at UFC 95 from London, but turned it down for similar reasons. He publicly said he wasn't ready, but this is the same guy who wanted to fight 3 weeks after his last one. Now he will ride Liddell's coattails to some decent money in April.
Looking at UFC 85, 93, and 95 you again notice there are no stars on these shows with PPV bonuses. The difference is hundreds of thousands of dollars and many viewers. It's hard to blame fighters' agents for taking this view, it is their job to maximize revenue for their clients while they are on top of the game. It's up to the UFC to bridge the gap.
Perhaps an enhanced scale for Europe is in order? The only problem is that the European shows, while profitable, are not exactly making a killing, and it's not clear yet that adding big names to those shows will make a big difference on PPV. It may just be that fans don't pay for PPV on tape delay.
This is a serious problem, and you could see the first effects at UFC 95 this weekend. The announced attendance of 13,000+ was heavily papered, as evidenced by the fact that the same attendance drew a significantly higher gate just last June. Even if you factor in changes in currency, the numbers are down by almost half. If they send substandard shows abroad they risk insulting foreign fans that rightly feel entitled to see top stars for their hard-earned money.
I don't think all hope of BJ defending in June is lost, I suspect the "negotiations" involve his team asking for more to fight there. However, I wouldn't be shocked if Wanderlei Silva vs. Rich Franklin is the main event of UFC 99.