16f88 @ 16mhz

What would cause strange readings on AN0 specifically? Here is the scenario, simple LM35 setup feeding output directly to AN0/pin 17. The temp reading is off by a couple of degrees. If I move the connection from AN0/pin 17 to AN1/pin 18 the temp reading is correct. Same thing goes for AN2/pin 1....it reads correctly. When I scope AN0/pin 17 (with LM35 output connected) I see the the clock signal with reasonable amplitude. When I scope the other analog inputs (with the LM35 connected) I see the clock signal again but a less than half the amplitude of AN0.

I've tried different 16f88's and LM35's with the same results

Looking at the internal diagrams of the 16f88 I can see that what I'm looking at is the internal switch but why would it be different across the board and how do I eliminate the problem. I've tried the suggestions in the LM35 datasheet but see no changes.


Please tell me the answer is not....just use the analog inputs that give you the correct readings...hehe