The first xdg-utils package is provided by slackware. The second (the one with the dj at the end) is provided by salix and it includes a few fixes that the slackware package doesn't have. If you haven't changed the package manager settings, it will always default to the salix package and it will always upgrade to that one. So if you manually install the slackware package, the package manager will always try to upgrade it. ndiswrapper is a similar case. The kernel was upgraded and the ndiswrapper package was upgraded along with it.
And as laprjns wrote: don't mess with the exclude settings unless you know what you're doing (which you don't).
Repeated updates of same packages
Re: Repeated updates of same packages
Yes, I am using vmlinuz-huge-smp-3.2.45-smp. Do I need to adjust any settings?