Accepting a pull-request results in 500 internal server error.

I'm currently trying to accept a pull-request but it always results in a 500 internal server error on this url:

POST: https://bitbucket.org/mediamonks/..reponame../pull-request/6/update-16-10-2012/fulfill\\
Guru meditation: 7d73b71ad2184474983ed2a26081112c$7eeb91517219778bc27c04ec514271f3

I've also tried it with the owning account and different browsers but it doesn't seem to help.

Any information would be appreciated !