Did you call it into DXT.BMP and resave as an extended biutmap???.....if not your sim will crash as you describe.
Garry
How do I do that?
First, if you don't have it, you will need the program, DXTBmp.
You can download it here, and it is free:
http://www.btinternet.com/~mnwright/programs/dxtbmp.htmNext, open the original texture that you are going to repaint in DXTBmp, and note what format it is,
like this:

Now, at this point, it's probably a good idea to save a copy as a 24bit .bmp,
as this is what most graphics programs work with.
This can be done like so:
NOTE! - don't save this copy in the same folder, as it
will overwrite the original file!! Save the copy in a different location.