Even the Struts folks say this is not a good idea. There are static memebers that would cause strange things to happen if shared accoss apps.
I was afraid that might be the answer. Supposedly Struts 2.0 will do away with the singleton model (http://www.twdata.org/backups/WW/comparing-struts-1-and-2.html), guess I'll just have to wait till then. Thanks!