The applyDecorator tag calls 'release()' manually, which clears the tag values.

As resin caches the values applied to the tags, this results in null errors.

This is explained in the mailing list post by Eric Kreiser on 15/1/03 to sitemesh mailing list:

"I had a problem with UTF-8 content when pulled thru the page:applyDecorator process.

The problem for me was directly related to doing multiple page:applyDecorator calls in a single page. The first call would render the UTF-8 content correctly, but all subsequent calls were miss handled. The first time the taglib is called the ContentType and Encoding is set correctly, but the second time the taglib is called the ContentType and Encoding is not set. And since the "release" method of ApplyDecoratorTag sets the ContentType and Encoding to null, they remain null for the second and subsequent calls - causing the content to be handled as 8859-1."