I have been able to do load balancing with IPX using Inetcfg utility. It was pretty easy. But, for IP, it was much more difficult. I only did it on a test server.
We have Dell NW5.1 servers with Intel nics. I searched Dell's site for an article named "How to Team Two Intel NICs" (TT1048189). After setting up the Autoexec.ncf manually according to the instructions it still did not work. I spoke at length with Dell tech support to find the typos in the article. Eventually, it did actually work. But, when I tried to load the configuration into inetcfg, it broke. Apparently, inetcfg could not load all of the parameters properly. That is as far as I got. Hope this helps some.