Ive had this same problem.
The thing is, the form generator add the line
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">to the generated forms, just delete them and it should work just fine.
WHEN RUN THE JBPM_SUITE.
IN THE RUN.BAT MODIFY AND ADD PROXY AND PORT:
rem Sun JVM memory allocation pool parameters. Modify as appropriate.
set JAVA_OPTS=%JAVA_OPTS% -Dhttp.proxyHost=192.168.xxx.xx -Dhttp.proxyPort=xxxx -Xms128m -Xmx512m -Dsun.rmi.dgc.client.gcInterval=3600000 -Dsun.rmi.dgc.server.gcInterval=3600000
I tried the solution with -Dhttp.proxyhost=... and -Dhttp.proxyport=... and it doesn't work...
I wanted to try the solution of webjavier but i don't understand it, if somebody could help me...
Thank your for your help.
It works with the solution of jcv, i added the doctype declaration in my form generator file and I suppress it in each forms.
So thanks to jcv and webjavier for bring me their help !