Well now what do we have here.
OMG! A wierdo buggery bug!Taken a quick look and it seems that the first page show the first 10 missions and the second page the next 10 starting from mission number 12.
Your mission is currently 11th on the list, and therefore doesn't show.
However if you sort by 25 everything is alright again and your missions is on the list.
Don't worry a thing, a minor bug like this can be fixed in no time (at least, as soon as a person who is resposible for the repairs comes back from his holiday)
Thank you dor pointing this nasty bugger out for us