No help yet

I've tried every USB port in every configuration as you described.

I tried different USB cables

I followed every step in the USB Audio Troubleshooting document except:

     - Purchase a PCI based USB card

          - but this suggests something about a chipset problem so I checked and my chipset does not match the list of known chipset issues, so I'm not sure this would work. Do you?

     - BIOS Performance Settings - I'll do this soon

     - DPC Latency (IRQ hogging)

          - I downloaded LatencyMon and it said that my system appears suitable for playing real time audio.  I can give you reports from that program if you think it would help

     - OS reinstall - not doing this

     - Hard Drive Reformat - not doing this

I will try it on a friends computer hopefully this weekend.

As I've said, I've tried every buffer size and every bit depth possible in everyplace I could find a setting for it and I explained what I did on my friends computer. 

Your telling me that I should take my pedal back to my friends house and ask him if I can completely change every audio, security, appearance, data management, and anti-virus setting on his computer?  I'm sure he won't mind that, right?  You have got to be kidding me. Wouldn't it just be smarter to try it on a third computer that's known to work, like say, at a service center? Or do POD devices not work without stripping your computer to DOS mode anyway?  I've spent over a week going in circles with you people and I know you can't give me any specific help because you don't have my computer in front of you. But what about my computer seems inefficent to you?  Its a gaming machine, quad core with 12MB L2 cache, 4 GB of RAM, USB 2.0, it far exceeds any of your "system requirements." So why have we been constantly blaiming my computer as the cause.  The obvious common thread between my friend and I is Intel G31 chipset with Vista 64 bit and my pedal.  So why don't you guys take my computer specs and/or my friends computer specs and run some tests on your Vista 64 driver?  In the meantime, I'll take this to a service center and they can test it there.     

I still need to take my POD to a service center so they can try to fix it.  But given the horrible technical support I've been given from these Line 6 "experts" my confidence is not very high for finding a resolution.  In that case, I will not hesitate to ebay this piece of junk and never buy another Line 6 product EVER again.  And I'll make certain that every person I meet knows exactly how awful Line 6 products are for computer compatiblility and technical support.  The best part is that they just assume the correct answer when the issues are clearly unresolved.  This forum is the worst form of customer service I've ever experienced, hands down.  So I hope it actually is a hardware issue, because that is the only saving grace I have for this nightmare of troubleshooting I've been through.

"If you have continued to test the POD X3 Live on other computer systems without results, please have a local Line 6 Service Center assess the unit for you and let us know what they find."

I took it to a Abel Audio which is my local Line 6 Service Center in Columbus, Ohio.  They took a month to look over and try to fix the unit.  On the bill it says he ordered and performed tech update #52, removed paint from the chassis back for better grounding on ground fingers, tried to reflow PC chips solder joints with heat gun, checked ground connections on USB chip, checked items suggested by line 6 technicians, cannot track down problem to a single component.  So now that I got the unit back home, I find that the top row of switches do not work and the home and input buttons are smashed in.  So now I can't even sell it because your service center only managed to break it even more.  I obviously have to take it back now and probably wait another month for them to fix what they broke.  But before I do I would like to know what my options are at this point.  Your service center guys tell me I need a new main board and it costs $300 and that its not covered under warrenty? Is he serious? After all of this the end of my story is I bought a defective product and I'm stuck with it, now more broken then ever...  If that is the case, how can I justify purchasing another LINE 6 product ever again.  I bought a $500 defective product, got dragged through the mud, then spent $30 dollars at a repair center just to have it broken even more.  Did he really talk to your technicians? Can't I send it directly to you guys? Is there seriously no way to fix this problem without buying a new unit?