We have no affiliation with ThePlanet. We have our servers in a different datacenter in Dallas, Texas (Colo4.com to be exact). We also have servers in Los Angeles, California which is in a colocation facility (don't think TP even has a presence there). So no link between us, that's for sure..
We have nothing to do with ThePlanet. My guess is your using an IPWHOIS which isn't reliable. Feel free to PM me the IP you see as this doesn't make sense and let me know the tool your using so I can take a look.
Conclusion is DNSstuff traceroute shows ThePlanet on top of the traceroute. That means DNSstuff uses ThePlanet for their servers. The bottom of the traceroute shows the location of the IP the OP saw which is our IP within Colo4.com's datacenter. Hope this clears things up.