vitesse, I think I know the answer to your problem. The container is not able to find your file to include. I have a theory why.
I believe your header file has an extension in the filename that Windows is not displaying (or you are not noticing). Browse to your directory that contains the header file. Each file in the directory should say the file type in addition to the name. It could say "JSP File", "JSPF File", "Text Document", "Rich Text Format", or another type. If your type says "Text Document" then your file is really named something like header1.jspf
.txt even though it looks like header1.jspf - which would explain why the container can't find the file.
By the way, your original posted code works great on my machine (aside from me not having a copy of that image) and I'm using Tomcat 5.
Someone said the
servlet mapping is pointless but it is not pointless in Tomcat I don't think. I believe Tomcat doesn't understand the .jspf extension convention and that mapping can be added to the web.xml to make it treat jspf files like a jsp.