[Android][Solved] Error in R.java file in android but no error in others files.

I feel difficult to explain what i mean in title, 

maybe see this picture will be more clear :

In "news_post" project, there is R.java have the error only.
So i tried to deleted the R.java and let it gen again.
But show "R.java was removed! Recreating R.java!"

ORZ

and I open the R.java and found sth strange.
Error with an image name !

After rename the image from 100x100_6 to m100x100_6,
Fixed the error !

p.s.

Finally I know, can't use an image name start with the number in the android project ....