Hi Andy
When you try and capture the ILS, are you already flying with the AP on (as opposed to flying manually then engaging the AP to capture the beam)?
What I did when I looked at the SEPP2 system on the Argosy last week (I think it was last week!) was to sit on the runway at KSEA and set the aircraft up for flight.. course deviation card set to the runway heading and course heading needle set to the same heading. I then took off and while in the climb, engaged the AP. The aircraft followed the runway heading until I'd reached around 1500ft then I engaged ALT. I turned the aircraft around onto a downwind leg using the heading adjust needle (but left the course deviation card alone at this point). At a suitable point, I turned the aircraft onto a base leg then onto the runway heading using the heading adjust needle. The radios were both set to the ILS freq.. the ILS MI lit to confirm this and both ILS indicator needles became active. When both were centred on the beam, I engaged GLIDE on the AP and the aircraft followed the beam down to the deck
It's good practice NOT to engage GLIDE until both the horizontal and vertical bars are centred.. this applies to a good many aircraft and failure to do so can have the model shooting off, doing it's own thing.. just when you DON'T want that to happen

You HAVE to be setup correctly on the glideslope even though with the model, you don't necessarily need to have both radios set to the ILS. This seems contradictory I know and you wouldn't really want to land with only one needle active (ILS freq on Radio 1 only) but.. with only Radio 1 set to ILS, if you're lined up correctly and your approach lights are 2xwhite and 2xred.. hitting GLIDE will still land you 'on the keys' without having Radio 2 set to the ILS
It may all sound very complicated but it's not really. What it is is different
So.. make sure the course deviation card is set to the runway heading.. make sure the heading adjust needle is pointing on the runway heading.. ensure both radios are set to the ILS freq (to get an accurate ILS indication).. wait for your needles to centre then hit GLIDE. Don't wait until you've flown above the vertical beam or you'll fly straight on. Fly into the beam from below and engage GLIDE when the needles are centred
ATB
DaveB
