hi i've recently installed slack on my samsung laptop. My trackpad encounters a simila situation. I don't consider it a problem though as mine is similar to a mac's trackpad and uses two finger click as right click, but like yours, the area that's normally considered the right click area on windows (which i hate mind you) does not work the same as on windows. Slack is described as 'vanilla' linux, in that the distro doesn't do much customization to the packages that get installed and they're installed the default way that the developer intended. I don't know for sure, but i think this may be related to your x.org file, and you may have to do some configurations to your x.conf file to get it to work the way you want. I'm still a newbie at Slack my self, so that's all i can do to help. The official Slackware forum is actually located on this sight, under forum, distributions, and then slackware. If you're serious about slackware you might want to mention your problem there.