URLs will often show multiple times in the access log because they are going through multiple phases (URI translation, auth, etc.).

Some suggesstions:

• Telnet to the server or use GET (from LWP) so that you can see the actual headers and HTTP traffic coming from the server.
• Make sure you loaded Apache::PerlRun.
• Turn on warnings: PerlWarn on.
• Did you really mean to make everything under /webserver/documents, including any images there, run though Apache::PerlRun? That is what you've done here.