I have the same problem in FS2002. I guess the autopilot do not watch the glide slope carefully 

I usually have to correct the pitch with the joystick.

I switch off the autopilot and autothrottle just before I start my descent for approach, but I watch my speed carefully.

On short final I try to have a speed of 155-160 KIAS. I don't think this is slow for a 737. It may even be a bit high, I'm not sure.

Spoilers are not deployed as well. I have a button assigned on the joystick to arm the spoilers.

By the way, bcstover: Does this happen only with the Lear Jet? I'll check if I have this problem with others, as well.

Quote:

You got me wrong, or I couldn't explain well. I mean the Top of Descent point. Nothing to do with the ILS at that altitude  .

When I'm getting closer to the TOD point (around 30-40 nm away from the airport, depends on the flight level I fly), I switch the autopilot off and start flying the rest of the route and the STAR (if I don't have the chart it is either the pattern entry or an ATC vectored approach)manually. After the last turn I make to turn to the runway heading, and get aligned with the rwy, I switch the autopilot on again, and press APP. Autothrottle remains off. It first seems to catch the glideslope but then falls short of the runway. It appears to be very slow to correct the errors.

I have found that sometimes the autopilot cannot be trusted to fly the ILS correctly.  Often the plane makes a late descent causing too steep of a descent angle and a short landing (as you described above).  In my view, there is no substitute for flying the ILS manually.

Practice flying the ILS manually, making small adjustments to the glideslope once you are established and you should land comfortably just over the threshold every time.

Try landing with the weather turned off.  Once you get the hang of the localizer and glideslope, turn the weather settings back on.  You'll be able to land in CAT III conditions in no time!

One other suggestion turn on the visual flight path using rectangles or hoops set the number of guides to max this will put a set of rectangles or hoops that you can see try to stay in the middle of these and you will make a perfect landing every time. 8)
These can be found in the aircraft tab on the main menu.
I have found these to be a great tool in learning the correct approach path. 8)
I would stay away from using auto throttle this is only going to make it harder for you.
PS
Rember auto pilot is not auto land. A lot of people think that by using the approach button that the plane will land itself. This is not true. As the button says APPROACH it will put you on the glide slope but will not autoland. FS2004 does not have that feature.
A true autoland system does everything from lowering flaps gear and adjusting power during descent it also goes into reverse thrust by its self. The pilot does not have to touch anything. The only thing autoland will not do is to taxi the aircraft to the gate.

hold on a minute nexus! you mean i can get planes to pretty much land themselves on auto pilot?