Some background:
When I purchased Maniaplanet on Steam, I bought Canyon first, and then purchased the other titles later. Because of that, my Maniaplanet directory is:
Steam\steamapps\common\ManiaPlanet_TMCanyon
...even though all the titlepacks, Maniaplanet.exe, etc. are in that folder, not just Canyon.
All the titles are listed separately in my Steam library:
Trackmania2 Canyon
Trackmania2 Stadium
etc...
I'm able to access any of the titlepacks via any of the listings (they all just open up the same Maniaplanet frontend/UI). As far as I can tell, the only difference is the "hours played" tracking, which tracks all of them separately, and increases depending on which title I opened (example: several hundred hours played for Canyon, 65 for Lagoon).
The point: If I start up Trackmania 2 Canyon via Steam, the Openplanet overlay shows up, and Openplanet functions. If I start up Maniaplanet via any of the other library titles, then Openplanet doesn't function. Nothing happens. No log update, no anything.
This initially made me think Openplanet wasn't working at all, until I started Maniaplanet via the Canyon shortcut by chance, and...oh, there it is.
I'm not sure if this is something that's fixable on your end (and it's certainly not a problem to work around), but I could see it leading to a lot of confusion (like it did with me), so I thought you might want to know about it.
Edit: There could be something else going on--my install seems to be sorta broken.
