Problems with trackback links on my site

hi,

i have a problem with the trackback links on my site (wordpress 2.8.4). when other blogs link to me in their blogpost normaly there would set an trackback link in the comment section on my site. but on the complete blog no trackbacks where displayed.

for example: my friend from this site http://www.einstieg-internet-info.de/index.php/allgemeines/super-chance-auf-ein-kostenloses-coaching-und-mehr has set an deeplink to my site http://www.digitale-infoprodukte.de/allgemein/gewinnen-sie-eines-von-7-startupchecklisten-paketen-sowie/ but on my site there is no trackbank link displayed.

but i don´t know why. pingbacks and trackbacks are allowed for every blogpost. Incidentally, I have yet not a single blog trackback throughout. thanks for any help!

regards tobias