How to Stop/Escape Code Expansion Insanity

I have been using Rubymine for about a month and I have this love/hate relationship going, hopefully it's just a painful learning curve issue.
I mean, ed, sed, ex, vi, emacs, textmate, eclipse, Xcode, Ludcid Emacs, ...,  haven't made me this crazy.

How do I stop/escape crazy code expansion?

For example! I am typing up a comment

# Data asserted into the[space]

After I hit a space after the word "the" it expands to "Then do

end"

WTF?

This seems to pop up every so often.

Another example is if I have a short variable "s",  I might use in an each loop, and hit space it expands to "session[:]"

WTF?

And how do I change the do block expansion?

It does this:
foo.each do
|var|
end

Not what I want! How in the world do I stop/escape/change this!

I prefer

foo.each do |var|
end

How do I stop the code expansion insanity?

Thanks.