I have been working on Win XP Home in my 2 exam rooms for the past year.
I encountered similar problem early on, and found out that the answer was to make sure AC is same version on all computers. Things have been working fine for almost 8-9 months.
Bert?s comment is absolutely right. I have 8 computers. My computer ?server? was XP Pro and now WIN 7, 64 bit. The rest are either XP Pro or Win7 Pro except for the two in my exam rooms. Pro version has made my life, dealing with the network, a lot easier.