Windows XP Pro and Netware

I have a Windows XP Pro SP2 machine on Novell Netware 4 network. I want two or three users logged to Windows and Netware simultaneously, so that one is working in the front, while the other/others perform unattended calculations in the background, within their sessions. This works fine on XP-only machine. Installation of Netware client (4.91 SP3) makes it impossible to have two or more users logged in. Novell Client takes over logging procedures and shows no option for simultaneous users (only logging out, no switching users is available).