Jade,
I get the same problem using IE6.0 on Win2k. I also experienced the same problem on one of my demo sites, but it appeared to be a result of installing a package I'm working on. When I deleted the package the redirection problem went away! I'm currently going through the code of my package to see if there's anything weird there. The demo site is using OACS4.6 and that's the only place I've seen with the problem. I'll keep you posted...
Michael