Headphone amp debugging help

[fishdds]

Hi guys,
I made the Headphone amp from the GGG site.  Well, it was one of those "fire it up and nothing happens" occasions that simultaneously causes the stomach to come up into the throat and the smoke to come out of the ears. :x   Anyway, I'm debugging it with an audio probe, and I get nothing after the 10M resistor labeled "R1", so I take it out and just connect a new 10M to the trace and I get audio, but when I put it back in the board I get no audio.  I also get audio into the input of the opamp, but then no further.  Anyone have any ideas.  Here is a link to the project:
http://www.generalguitargadgets.com/index.php?option=content&task=view&id=134&Itemid=166
Thanks for the help.
-David

[petemoore]

I'm debugging it with an audio probe, and I get nothing after the 10M resistor labeled "R1", so I take it out and just connect a new 10M to the trace and I get audio, but when I put it back in the board I get no audio. I also get audio into the input of the opamp, but then no further
 Take pin voltages off the opamp pins each to ground.
 depower / Use the DMM to see if somehow ground is getting in somewhere it shouldn't, like around the OA, pins except pin 4. Check all grounds are connected to ground.
 read about OA biasing, and think of ways to apply the DMM.

[fishdds]

Ok, here are the pin voltage readings:
Pin2= 6.51
Pin3= 1.22
Pin6= 5.32
Pin7= 8.11

This is a single channel opamp.  Here is the data sheet:
http://www.fairchildsemi.com/ds/LF/LF351.pdf

It calls for a TL071, but this is the same, right?
The only other thing I did differently was use an 500k audio pot instead of reverse audio.  That doesn't make a difference, does it?  Everything appears to be grounded that needs to be.
Aaargh!
Thanks for your help.