VPN connection problems

I am having a problem connecting with my XP Pro laptop to my SBS2000 over a
VPN. I take this laptop to work and it works fine but when I take it home,
it is a nightmare. It will connect via VPN without any issues. However, my
Outlook 2003 cannot synchronize my folders and I am unable to copy files to
the server from my laptop. If I try to copy 10 files, 2 or 3 will get there
but then it times out. The problem seems to very random, as somedays I have
no problem with Outlook. I do not often copy files. I have this problem on
two laptops. Somebody HELP!!

Thank You