Lpc2000

I have several pins configured as capture pins which interrupt on
either a rising of falling edge.  Then in the interrupt handler
I read the IOPIN register to get the value.

According the description of the IOPIN register on page 81 of the
Philips 210x User Manual, this should work.  I quote:

  "The current state of the port pins can always be read from
    this register, regardless of pin direction and mode."

But it doesn't seem to work.  I have double and triple checked
my code, and I 95% sure this is not a software bug.  The capture
pins always read zero.

Is the user manual wrong?

    -bob