Skip r_mode check? How do you think it? You can't really force engine load something, but skip something else.
I've been googling around to see if anyone found a permanent solution for the problem, but I can't find anything.
Creating a configuration file and executing it each time the map loads seems like the best thing to do. Open a Notepad and copy/paste this into it:
/r_mode -1 /r_customwidth 1366 /r_customheight 768 /cg_fov 90 [SIZE="1"](or whatever value works best for your screen size and/or desired resolution)[/SIZE] /vid_restart
Save the file (give it any name you want, something like "Fix", for example), change its extension from .txt to .cfg and put it to your Base folder. Run the game, load any map you want, open the console and do /exec Fix. I'm not sure whether that will work or not, but if it does, it should automatically switch the game to widescreen mode, saving you the trouble of changing those values one by one.
It won't fix the crashing problem on map change, though. To avoid that from happening, exit to main menu (I assume the game stays in widescreen mode when you exit to main menu) and change the resolution from there to some "normal" (non-widescreen) value, load the map you want and execute the "Fix" again.
Note that I have never done any of this myself, so forgive me if it doesn't work. I r n00b. =p
I'll try that when I get off work today. I still think it's odd that I can't change any of the original r_mode's values to 1920 x 1080, thus negating the r_mode -1 error. It's also weird as I used to be able to do this whole process no problem on my older machine which leads me to believe that hardware most certainly is a factor.
Thanks a lot for your help, guys. I'll get back to you later to see if the .cfg strategy works.
EDIT: I created a "fix.cfg" file, put this inside:
r_mode -1 vid_restart
while in game, in the console typed "exec fix", worked like a charm. Still tedious to do, having to remember when switching maps or exiting the game, etc.