shorewall blocks apt-get

["Benedict Verheyen" <linux4bene@pandora.be>]

Hi,

i configured shorewall on my server to share the internet connection.
My apt.conf file contains a line to configure the use of the proxy
of my isp: 
Acquire::http:Proxy "http://proxy.isp.be:8080";;

However when i do an apt-get it gets stopped by the firewall.
apt-get install menu result:
===========================
Reading Package Lists...
Building Dependency Tree...
The following NEW packages will be installed:
  menu 
0 packages upgraded, 1 newly installed, 0 to remove and 6  not upgraded.
Need to get 398kB of archives. After unpacking 1442kB will be used.
Err http://ftp.belnet.be testing/main menu 2.1.5-14
  Something wicked happened resolving 'proxy.isp.be:8080' (-3)
Err http://ftp.belnet.be unstable/main menu 2.1.5-14
  Something wicked happened resolving 'proxy.isp.be:8080' (-3)
===========================

kern.log:
===========================
Nov  2 22:59:06 arthur kernel: Shorewall:all2all:REJECT:IN= OUT=eth0 
SRC=213.224.96.7 DST=195.130.130.133 LEN=73 TOS=0x00 
PREC=0x00 TTL=64 ID=3453 DF PROTO=UDP SPT=32768 
DPT=53 LEN=53
Nov  2 22:59:06 arthur kernel: Shorewall:all2all:REJECT:IN= OUT=eth0 
SRC=213.224.96.7 DST=195.130.131.5 LEN=73 TOS=0x00 
PREC=0x00 TTL=64 ID=3453 DF PROTO=UDP SPT=32768 
DPT=53 LEN=53 
===========================

I checked the shorewall-users mailing list/goolge but didn't find anything
on this problem. Does anybody know how to solve this so i can merely 
apt-get again?

Thanks