Canon G5, E-TTL, external flash and M-mode

Gisle Hannemyr wrote:
I use a Canon Powershot G5 with a Canon 550EX Speedlite mounted in the
hotshoe.

If set the camera to P, Av or Tv mode, the E-TTL logic controls the
output of the flash fine, but it also assumes that I want "fill"
flash. I.e. Av-mode gives me a too long shutter speed, Tv-mode mode
gives me a too wide aperture, and P-mode messes up both.

Hoping that using M-mode (manual) would fix this, I turned the mode
dial on the camera to M, set shutter speed and aperture, and made sure
that the flash (550EX) still was in ETTL-mode. What happens when I
press the shutter release is that the flash fires at full power.

I.e. it looks like on my G5, I lose the ability to use E-TTL to
control flash output power when I set the camera in M-mode.

When I asked the DSLR newsgroup about this, they responed that on
the 350D and 20D (at least), switching the camera mode dial to M,
flash power is still controlled by E-TTL as long as the flash itself
is set to ETTL.

Is the behaviour of my G5 normal (i.e. do other Powershot owners
experience this)?

Is there some menu setting that I've somehow tripped over that has set
the camera do behave like this - and can it be reset?

I've RTFM without getting any wiser, and I've thumbed through all the
menues. What I want to do is to set the shutter speed and aperture
myself, but retain E-TTL for controlling the flash. Any help will be
appreciated.

Not exactly the solution you are looking for but maybe it helps
nevertheless if you cannot get it resolved differently. I have a G5 and
an Metz flash which is too old to be able to deal with E-TTL. When using
the flash I set the camera to M choose shutter speed and aperture that
suit me (depending on the situation) and let the flash do the lighting.
Interestingly enough zoom adaption of the flash still works.

Kind regards

robert