I am right now trying to install dcm4chee on CentOS and I experienced the same problem. When I was looking for a solution I saw your message here, as well as your message on the newsgroups with some hints about possible causes and solutions.
It would be interesting to point from here to the newsgroups thread with answers and additional information, since that could help to other users having the same problem
In short: The problem is WADO service unable to start due to the JAI Image IO library not being properly installed.
You should download the 64 bit version of the library for Linux, extract the files and replace just the original (32 bit) ones from those that you downloaded.
$ cp clibwrapper_jiio.jar $DCM4CHEE_HOME/server/default/lib
$ cp jai_imageio.jar $DCM4CHEE_HOME/server/default/lib
$ cp libclib_jiio.so $DCM4CHEE_HOME/bin/native
Now, your DCM4CHEE installation should be able to run on your 64 bit Linux machine.