You must use the J4 libraries supplied in the distribution.
Running under Weblogic 8.1 requires tuning some of the packages TLD files. Weblogic 8.1 will not render a page containing a TLD that it believes is invalid.
There is an indeterminate list of conditions that may cause TLD invalidity, including:
Currently identified issues include:
PutTagclass not found.
One possible solution for fixing these is to unpack the offending jar file, edit the TLD and comment out the problems areas, update the original jar, and redeploy.