Thanks for the input folks. I'm happy to hear that some are not experiencing any problems at all. Here are some quick answers to the questions asked...
What was it that made you revert anyways?
I like to run long challenge games, that is, challenges that will take a long time to complete. I made two runs in 40.24 that crashed, once almost immediately and once after several days. It was disappointing but I don't hate the game or anything, just inclined to move back to a more stable release.
Trees cause the game to crash...
That's probably not the case here, the challenge I was attempting was in a treeless biome. Nothing but sand and clay, lots and lots and lots of clay.
Are you sure your issues are caused by dwarf fortress itself, and not a third party tool?
No, I'm not sure of that. It could very possibly be a 3rd party tool, however I don't use many. I was running the new lazy newb pack, Gemset tileset, dwarf therapist and dfHack. I don't use dfHack for anything though, other than one little command right in the beginning which could be the problem. I'll have to test. If it's the problem, I'll make a new thread about it.
Hmm... I used to have crashes in the recent 40.xx versions, but once I flagged DF to be Large Address Aware, it stopped crashing. Perhaps it the crashes are caused by DF2014's increased complexity in comparison to 34.11?
I'll have to try this as well. I didn't realize that it still had to be flagged manually, for some reason I thought that happened automatically now. I'll take a look.