The problem with this piece of code generated for my JSP by tomcat4.0b6 is that it catches Throwable t and then call pageContext.handlePageException(t) which takse Exception NOT throwable !! as parameter as a result I am getting class cast exception: org.apache.jasper.JasperException: Unable to compile class for JSPnullD:\java\apache\tomcat4\work\localhost\usorg\_0002forgunits_jsp.ja va:225: Incompatible type for method. Explicit cast needed to convert java.lang.Throwable to java.lang.Exception. if (pageContext != null) pageContext.handlePageException(t); ^ 1 error ============================================================== } catch (Throwable t) { if (out != null && out.getBufferSize() != 0) out.clearBuffer(); if (pageContext != null) pageContext.handlePageException(t); } finally { if (_jspxFactory != null) _jspxFactory.releasePageContext(pageContext); } ==============================================================