BOINC 5.4.9 uses only port 31416 as I said in my other post.

What kind of computer do you have? CPU, RAM amount, Operating System? How much is running in the background on startup?

What version of BOINC are you using?

Older versions use port 1043 for communication between BOINC manager and BOINC.exe, it has been found in the past that this port was hi-jacked by MS Outlook and Outlook Express. Port 1043 is the port allocated to BOINC by the relevant authorities. There is also a suspision that the ATI graphics control centre also used this port.

But rather than wait or fight these commercial enterprises, the later versions now use port 31416. This as far as I know has cured most of the problems.

You need to do some investigation into which programs are using which ports, for any further investigation to take place.

Andy

edit/ to check wwhat is using ports in WinXP run cmd then in that window;

you might want to make sure that nothing else is using port 1043 on the affected hosts, you can do this by running

netstat -a -o

from a command prompt, this will show you the process ID (PID) of the app which is using each port, look for port 1043 (the usualy notation is either an IP address followed by the port, seperated by a colon (127.0.0.1:1043) or a dns name in place of the IP address (localhost:1043))
use the "processes" tab in the windows task manager (you'll need to change the options to display the PID column) to see which process has port 1043, it should be boinc.exe, if not, find out which app is using the port (it shouldn't be, becuase port 1043 is allocated to boinc)
if it's a file name you don't regognise, enter the filename into your favourite search engine and it should return some results describing what the process does, and what app/suite it's part of

This was taken from a post on the Seti Question and Problems board.