Okay, I checked the link on SlackBuilds.org for the NetBeans source verses the links to download NetBeans 6.8 from NetBeans.org and they're different.
So what I did was modify the link from SlackBuilds.org to the following and edited the SlackBuild script to reflect the correct version and date info:
Here's the source to download from NetBeans.org:
And you can just use the existing SlackBuild for NetBeans 6.7.1 from SlackBuild.org (Don't forget to change the version in the script to 6.8 and the date to 200912041610 or whatever is tagged on the file you get from NetBeans.org) before building.
I also now have prebuilt Slackware packages for NetBeans 6.7.1 and NetBeans 6.8 if you would rather just install the Slackware package.
msg me if that's the case, and I'll prolly put it up at http://Slacky.eu
so anyone who wants it can just d/l and install the package.
All is good