Endless underground?

hi!
I have been digging down on a penumbra planet for ages... straight down, 5 to 10 times longer than usual and still can beam up when I remove some background tiles. No real changes in blocks and only small amounts of ores also, just like near surface. (Penumbra planet, with weird whisperings at night..) actually quite fitting, with those madness- voices... feels like going insane Where am I? Which direction is up?
So not that much of a problem, but still would like to know if it's a bug or a feature. ( digging up or sideways didn't change anything)
Oh- I am using FU, by the way

 

Sounds like you found one of those super sized 64000 sector worlds. The new interface seems to lack a read-out for size of the planet now, which would be nice if that gets fixed. But if the planet still looks really big in nav screen, chances are its one of the super giants.