I still did not meet your issue.
Which OS with Inventor 2009 did you use?
Here I need you help to try the steps as below:
1. Launch Inventor 2009
2. Unload some add-ins except T&P and Content Center on Add-In Manager(Tool->Add-Ins..)
3. Close Inventor, then re-launch Inventor.
4. New one single project
5. New an assembly and save it
6. Create one pipe run.
7. New route, see whether it works.
Thanks,
Ruth Hu(Autodesk)