[TYPO3] problem: pdg_generator2 works only once

[Martin Bless]

I'm having a problem with pdf_generator2 v0.5.1 within TYPO3 v4.2.1
using Firefox or IE.

PDF generation works well the first time I klick the link. Klicking a
second time makes Acrobat Reader come up and complain: "Diese Datei
ist beschädigt und kann nicht repariert werden / This file is damaged
and cannot be repaired."

If I clear the page cache or if I'm logged in as a BE user
pdf_generation works. My conclusion: The problem has something to do
with the caching feature.

Q: Is ist only me having this problem?
Q: What can be done about it?

Thanks and "Have a nice day!"

Martin