Wrong type argument: integer or marker-p: remove until

[edubkendo]

I have rsense set up with emacs. I have followed the installation and setup procedures very carefully.
I'm on

Ubuntu 12.04
ruby 1.9.3p327

I have also tried it with

jruby 1.7.2 (1.9.3p327) 2013-01-04 302c706 on Java HotSpot(TM) 64-Bit Server VM 1.8.0-ea-b72 +indy [linux-amd64]

When I try, even the example from the screenshot on rsense's homepage:

File.open("foo.txt") {|f|
  f.each {|line|
    line.
  }
}

when I try to get completions from that . I get the error:
Wrong type arguement: integer-or-marker-p, :remove-until
Other attempts to complete a method get the same result. I really want to get this working, and ultimately would like to make a plugin to get it to work with sublime-text, but can't seem to get anywhere. Thanks.