Yeah I am too. What you have to do is turn on your Rangefinder (SHIFT + O) then enable the Optical Seeker (Key O) then move the pipper onto the target (doesn't have to be preplanned) and lock. At this point you have to map "Launch Permission Override" somewhere on the joystick as it's needed to launch the weapon. Now the tricky part, if you're not familiar with LGB use, Su-33 wise, is that it needs to fall within two bars on the left hand side of the HUD. Usually a diving or semi-level attitude will get you within the bars. If all fails, nose up and climb slightly to get a better "window". Note you have to designate for the GBU's while the KAB-500s are launch and leave.
Here's a track of me using them (for the screenies) that could help:
http://562.50megs.com/LOMAC/Tracks/gbutest.rar
Lock On 1.12
That should help more than swamping the topic with alot of screenies... I post enough as it is..