pdf invoices returns blank page on freebsd

[khinester]

hello,
i recently moved my server to a freebsd 8.1 box, all seems to work so far, but for one small issue, which is that when i click in the BO on an Invoice, the page returned is just a blank page.
on my development machine which is OSX, it works fine, so i am guessing that i don't have a specific php or a pdf port installed.

here is a list of all the php modules that i have compiled:

# php -m displays
[php Modules]
bz2
Core
ctype
curl
date
dom
ereg
exif
gd
hash
iconv
json
libxml
mbstring
mcrypt
mhash
mysql
mysqli
mysqlnd
openssl
pcre
posix
pspell
Reflection
session
SimpleXML
soap
SPL
standard
tokenizer
XCache
xml
zip
zlib

[Zend Modules]
XCache

i also have the pdflib-7.0.4 installed.

but to no avail.

any advice much appreciated.