I have all my php files on a network drive for use on my development server. When I save files in nusphere phped it seems to take 5 seconds or longer. I have a habit of saving very often (lost too much work in the past by not doing it), but if it's taking me 5s+ every time I save then it gets quite annoying after a while.

I have had no problems saving with other IDE's (e.g. Zend Studio), just with phpEd.

Can anyone help?

did you check "create backup" checkbox? or something like this? Did you enable compression on the server volumes?
I'm saving on my windows2003 server with no delay at all.

Everything is default. "Create backup" is not checked. No compression is enabled. Saving onto a samba share on Redhat Enterprise Linux 4.

Is your machine added to Windows Domain? Right click on My Computer, Properties->Computer Name->Change
it will show you if your machine is part of Domain.
In case of domains, file io operations may take longer when working with samba shares.
Also should be noted, that PhpED may save longer because it does save carefully, it first saves into temporary file in the same directory, then remove old copy and then renames temporary to old name. In case if save operation fails, you won't lose your file. I'd recommend you to turn on debugging logs for samba and check what causes it to run slow. Perhaps it tries to resolve your machine name using netbios or dns lookup. More operations may result in more lookups and poorer performance. If the problem is in loopups, I'd recommend you to store your machine IP with it's hostname in the RH's /etc/hosts