We ran into some code signing issues getting a beta update out yesterday and ended up recreating all the certs/profiles for the Wikipedia iOS beta distribution channel.
It looks like this has the side effect of preventing the old version from installing or running anymore. Awesome!
I've just send out an update ping for the version we tried yesterday with the new cert, which runs ok for me.
This version *should* work where the previous one did not. As an additional plus, it'll sit side-by-side with the store version! So you can delete the old beta and reinstall the store version if you want to have them both installed at once.
We plan to change the beta version's icon to help users distinguish them in future.
Sorry for the inconvenience...