Forum status icons image replacement
 

I'm running into a issue with replacing the standard status icons with ones that i made.

I have successfully replaced all of my status icons except for 3

thread_dot_new-30-right.png
thread_dot_new-30-left.png
thread_dot_lock_new-30-left.png

Every time i try to change the image it gets reset by the standard one,but if i rename it it's fine.Any thoughts as to what could be causing this?Or were is the code i would need to edit to use them with a different name, I have done a search in the style manager and only found 1 in the .css file and tried changing it there and it took away the image all together

Thanks