When setting up a new job (for organization ABC) and successfully entering the
subversion authentication options using username & password (and its able to
connect), Hudson will then clear out the username & password it has stored for
other jobs (organization XYZ) which also use the same SVN repository. Pulling
up the configure page for those other projects will reveal that it is no longer
able to access the SVN repository (i.e. "Unable to access"). Any attempt to fix
it here (for organization XYZ) will break the credentials for the other job
(for organization ABC).

The only quick workaround is to have both jobs share the same username &
password to the SVN server, however this poses a security risk since this
account will then have access to other organization's source code. A second
(painful) workaround is to just setup another instance of hudson on a separate
port for that other organizations jobs.