[Icecast] icecast 2.4 check if source exists?

[uno]

hello,

i've upgraded to 2.4. in order to use url-auth etc.
works fine, but now i have a problem:

i've to check if a source exists. i did so by fetching
headers for a mountpoint, example 

wget -S http://server:8000/test

if a mountpoint existed in icecast 2.3.2 (my previous version),
it returned something like "200 OK", when a source was connected.

now in 2.4. it always returns 200 OK, means the stream at this 
mountpoint exists, whether a source is connected or not.

how can i check (programatically) if a source / active mount 
exists or not?

thx, uno