After installing widescreen mod, widescreen GUI, and Baldurdash fixes in BG1, I was experiencing random crashes to desktop when entering areas. More frustratingly, the mouse scrolling would not work at all down or to the right... Diagonal up and right was okay, diagonal left and down was okay, but pressing my cursor to the right or bottom sides of the screen had no effect whatsoever.

Reinstalling the widescreen mod and disabling multiple resolutions (I was using 1280x800 anyway) seems to have fixed both issues.

Hopefully this helps someone else out there, as I was unable to find any solutions to the mouse-scrolling issue.

You didn't install them in that order, did you? Fixpacks should be installed first, the Widescreen Mod always last, except if you do a GUI change, even after the Widescreen Mod. So proper order is Fixpack - other mods - widescreen mod - widescreen GUI.

Did you install the widescreen mod after starting a game? I had a ton of issues with Planescape when I tried to use my 1440x900 saves after reinstalling to a 1280x720 resolution and most of them were the same ones you listed.

Basically, if you reinstall the widescreen mod to a new resolution, you pretty much have to start a new game.

I'll clarify that I don't know how true this is for Baldur's Gate, but I imagine it's a problem across Infinity Engine games.

Ah... Totally missed that. I think somehow "install the GUI mod after the widescreen mod" became "install all mods after the widescreen mod" in my head. Thanks.

Although... It doesn't seem like that would be the problem with widescreen mouse-scrolling. I mean, I rule nothing out, but that seems like an exclusively resolution/GUI problem. Nope, mods were the first thing I did after installing the game. *shrug*