3750 Poe problem

I have 4 WS-C3750V2-24PS-S   connected in stack.

Switch 01

WS-C3750G-48PS-S

Switch 02

WS-C3750-48PS-S

Switch 03

WS-C3750-48PS-S

Switch 04

WS-C3750-48PS-S

xx01#sh power inline

Module   Available     Used     Remaining

          (Watts)     (Watts)    (Watts)

1           370.0       29.0       341.0

2             n/a        n/a         n/a

3           370.0       29.4       340.6

4             n/a        n/a         n/a

but when I try to connect a Poe phone in modules 2 or 4 it doesn't work.

Any idea why the watts available says n/a?

xx01# sh env power all

SW  PID                 Serial#     Status           Sys Pwr  PoE Pwr  Watts

1  Fixed                                            Good

2  Fixed                                            Good

3  Fixed                                            Good

4  Fixed                                            Good

Regards and thanks

Ok, Herman.  Can you post the output to the following commands:

1.  sh switch WS-C3750X-24P-S   detail; and

2.  sh version