It sounds like your interface (the non-3d part) is not getting the fov change. Did you change any obscure settings in a config file somewhere that you may have just forgotten about?
Edit:
Just saw this in the OP:
moving from crt to my 24" mon
Questions:
1) Are you still using your VGA connection (the blue one that your crt was hooked up to) or did you switch to DVI (the white one) when you hooked up the lcd?
2) If you are still using VGA, did windows pick up the monitor change? you can tell this from the list of available resolutions in the display options. The list should be rather limited in its number of options with the new monitor compared to what it was with the CRT.
3) If windows sees it, does TF2? Do you have to change the aspect ratio option in the TF2 settings to list the different 16:10, 16:9 and 4:3 resolutions, or does it list all of the 16:10, 16:9 and 4:3 resolutions together?
4) Do any of the other Source engine games (Half Life 2, Portal) do this?
Also, where did you change your FOV? I've never seen (or needed) an option like that in any Source engine game, aside from the console.