Okay, something is massively wrong with the StrangeProgram map...
http://osu.ppy.sh/s/5774Warning, long story incoming~
I downloaded the map a long while ago and played it several times, everything was completely fine and worked properly. A few days ago, a friend of mine, me, and a third person were playing in Multiplayer. One of the maps we put up was StrangeProgram. The third player didn't have the map, so he downloaded it. When the download finished, he could hear the music correctly, but it still said "no map". Neither F5 nor leaving and rejoining the game helped, and there also was no "Update" button for him.
Just to test if it worked, we gave him Host and suddenly it said that he had the map and the other two of us were marked as having "no beatmap". Same story, F5/rejoining didn't help. We did, however, get the Update-button (which doesn't really make sense to me since the map has been approved for a while and we always had the newest version). The Update-button, however, didn't do anything. You could click it as often as you like, nothing would happen.
Next, we all tried redownloading the map. My download via osu!direct didn't change anything and the same problems occurred. When I manually downloaded and imported the map via my webbrowser, it suddenly worked and we could play.
Now, I thought this would have solved the problems and I just wouldn't have to worry about it anymore.
Then, something strange happened today. I was spectating someone and requested he'd play StrangeProgram. He did just that but osu! told me I didn't have the beatmap and showed me the regular osu!direct popup that you get in that scenario. I just redownloaded the map, hoping that this would solve it but it didn't.
I tried opening the Songs Listing to check if anything needed an Update or something. As it should, osu! searched for recently imported maps, found StrangeProgram and started playing the music and showed the scores on the left side. It did, however, not show me the actual beatmaps. When I typed "strange" to find the map manually, it found no matches:
I entered Spectator mode again and could actually see gameplay this time, but only for the Taiko difficulty. Whenever the host would change to a different difficulty, it would once again say I don't have the beatmap:
(As you can see, the media player in the top-right corner also says StrangeProgram, meaning that it found the song~)
Now I am really confused. Manually downloading the map didn't fix it either this time...