QNX4, Samba 2.0.7 and Windows XP

I’m having a strange problem with Samba 2.0.7 where files decide that they can’t be written on the share. No problems when logged to the machine itself. Sometimes opening and saving the file via vi on a telnet session allows me to save it again over the share, sometimes not. Sometimes it simply decides that a file can’t be read at all.

Anyone else come across this problem? At this point I’m guessing its because I’m running XP with an old version of samba; more recent versions won’t compile since it tells me file locking is missing.

Is there a known work around for this problem?