Had a problem that I know I have solved previously, but that took me too much time to resolve this time because I could not figure out what to do. So this is a note to make me remember exactly how to fix it next time.
The problem: subversion was constantly asking me for a password, and not just caching the last used password as it should. This was probably due to me changing the subversion password, and subversion did not update the password like I would have expected.
Solution: Remove previously cached authorization in $HOME/.subversion/auth. There can be multiple files there, but I just simple removed the directory to force subversion to recreate it. Upon checking out code the next time, the password was cached as I was not asked again.