I am a recent buyer of UKB and there results announced today seem to be good. Anyone know why their share price dropped on this seemingly good news?

... and UKB has no US exposure so is unaffected by the US legislation.

Of course, that is the attraction of UKB.
Have a look at LNG, which is the total opposite, with big exposure to U.S. Absolute disaster.

Since prize funds are determined by number of users and spend per user, anything with such massive US exposure will be giving away such tiny prize that they won't be worth playing.... unless they can takeover a company with a large number of non-US users... like UKB.