Here's where I've gotten so far. I put a slit in the side of your tube for access to drag it using contact sets, but I think it's almost bound up. I show .003 mm clearance at this point to the outer end of the "plug".
My computer is also a dog, but at least it doesn't crash. Dragging to this point has been a very tedious task, but in all fairness, it's a really tough mathematical problem, too. If it won't move, try picking a different point on the plug, or changing your viewpoint, and it will usually move somehow. But the closer it has gotten to binding, the more difficult to drag, so this isn't exactly an elegant solution.
Sam
HP Compaq DC7100CMT
Pentium 4 3.00 GHz
2 GB RAM
Nvidia Quadro FX 1400, driver 8172, DX3D mode
Windows XP (32-bit)
Inventor Suite 2010 RTM