Transparency problems in winmip

Okay, I am at my absolute wits end with Winmip2. I want to change one of the .mips that has transparency, but every time I try and change something it just flat out refuses to do anything with transparency. I load in my new edited .bmp, double check that all the settings are as they should be, set the Invis. Color to magenta with shift+click, and save the .mip. Then I re-open it, and see that the Invis. Color has completely disappeared - not that it's not registering a colour, but the whole field is just not there. I then switch to type 4, reset the color to magenta, save, close, reload, and the colour is now black. So I try setting the part I want to be transparent to black on the .bmp, overwrite it with the new file, and still it won't accept it. If I try and directly save the .bmp as a type 4 instead of a type 10 (what it defaults to), it just spits errors at me; specifically, Error in BmpToTyp4, and then 5 Error in Typ4Subim errors in a row. I'm probably missing something really stupidly obvious, but I can't for the life of me figure out what.

What exactly are you trying to do?

Assuming you selected NR2003 for the mip type at the top...

Some mip types require a black and white transparency map, where white is opaque and black is transparent.

If you're replacing an existing mip, make sure all the information (sub-lm, tpye, mapp and priority) in your mip is exactly the same as the one you're replacing... or bad things may happen.

Cynon wrote:What exactly are you trying to do?

Assuming you selected NR2003 for the mip type at the top...

Some mip types require a black and white transparency map, where white is opaque and black is transparent.

If you're replacing an existing mip, make sure all the information (sub-lm, tpye, mapp and priority) in your mip is exactly the same as the one you're replacing... or bad things may happen.

I'm trying to modify the flag box and some building meshes. I do have NR2003 selected as the mip type.

I have noticed that some mips require a black and white transparency map, with the map saved as *filename*_ti.mip, but in this particular instance, trying to do that just crashes Winmip.

I have also made sure that all the information matches up - before I save new .mip, I open the original to double check that everything is right, but regardless of what I do, once I re-open the .mip, the transparency information is gone.

The track I'm working on is Bathurst V2.0 here.

It's much easier to use tga image files for NR2003.
When you convert the original mip to an image file with winmip2, convert it to tga rather than bmp.
Tga files retain the invisible color via an alpha channel, bmp files do not (that's why the ti mask is needed).
Make your changes in your paint program. (If your changes encroach on the transparent areas you'll have to redo the transparent layer.)
Save. Convert new tga image to mip.

I've seen that mentioned before, but there's no option for me to convert it to a .tga that I can see. It's just bmp, mip, and stp.

Ah. I thought I might've been missing something embarrassingly obvious like that.   

Thanks.