Notices

Recently OM has been making my N900 crash and reboot, before it's fully loaded (i.e. before start page w/ speed dial shows up). I reinstalled it, same problem. Any ideas how i could start trying to find out what's the reason for this?
thanks Ben

You could try removing the opera configuration/cache directory:

Cool, it seems that helped! But what caused the problem in the first place?

Also I'm wondering: Could I have fixed this if I had the same problem on a different smartphone, say, Android or Symbian, with no tool like x-term available?

Probably a corrupt/truncated configuration file. This would generally be caused by a crash while writing the file(s) but could also be just a random corruption (there's always a tiny chance of memory getting randomly corrupted).

I've no idea about Android. I think Symbian ties the data and application together a lot closer, so removing the application would have cleared up the configuration/cache data as well, but it's been a while since I've done anything with S60 so I could easily be mistaken. If it doesn't tie them together then you'd need to poke around inside the Symbian filesystem (using a decent file manager - the built-in one almost certainly wouldn't be any use) and track down where it actually stores this data.