Hi there,
I've just tried the following code and for me, it worked fine.
autocam on:backdrop on
load image "grass.bmp",1
make matrix 1,4000,4000,100,100
prepare matrix texture 1,1,1,1
point camera 0,0,0,0
update matrix 1
do
mx#=mx#+mousemovey() : my#=my#+mousemovex()
rotate camera 0,mx#,my#,0
color backdrop rgb(0,0,0)
loop
end
As you can see, all I have done is changed the file for a bitmap (I've also tried it with a jpg and it works), and removed the single quotes and square brackets which I'm sure you've done.
Unless you give any more information, all I can think is that you have the wrong picture name.
Sorry not to be of more help and Happy Christmas.