#6 blank page on back button

[Anonymous]

I'm in desperate need of help for the following:

http://test.bashen.nl, here you can find a little
script I made and by using html2pfpdf I generate a
PDF file of a random page.

- click on a random house

- click on PDF (top-right)

- PDF will open up

HOWEVER, when I close the PDF file en press my
Internet Explorer back button I get a blank page..

not always, but most of the times - I would really
like to take care of this for sake of customer
friendliness..

the problem arises mostly when I start my browser
fresh (so IE is totalle closed, I open the browser
for the first time, type in http://test.bashen.nl en
follow the above steps, press BACK button,.. boem..
blank page.. very annoying)

i certainly hope somebody can help me!