I've changed from using gdm to using a 'compiled at home' copy of wdm and, after a little configuration, that has resolved the problem. I now have cut-and-paste working again between Windows and my Linux desktop.
Thanks for all the help and suggestions. I quite like the simplicity of wdm anyway, I don't need any of the extra glitzy add-ons of gdm or kdm, the only reason I moved from xdm was because the Slackware 10 version woudn't work for me. -- Chris Green ([EMAIL PROTECTED]) "Never ascribe to malice that which can be explained by incompetence."