`marshal data too short` error message while installing watir-webdriver on Windows XP

Question

I have a clean installation of Windows XP (Professional, Version 2002, Service Pack 3) in VMware Fusion virtual machine (3.1.2 332101). (Host machine is MacBook Pro, Mac OS 10.6.7.) XP installation has 512 MB RAM and is fully updated, except I left Internet Explorer at version 6.

I have installed Ruby and RubyGems:

C:\Documents and Settings\zeljko>gem env
RubyGems Environment:
  - RUBYGEMS VERSION: 1.6.2
  - RUBY VERSION: 1.8.7 (2011-02-18 patchlevel 334) [i386-mingw32]
  - INSTALLATION DIRECTORY: C:/Ruby187/lib/ruby/gems/1.8
  - RUBY EXECUTABLE: C:/Ruby187/bin/ruby.exe
  - EXECUTABLE DIRECTORY: C:/Ruby187/bin
  - RUBYGEMS PLATFORMS:
    - ruby
    - x86-mingw32
  - GEM PATHS:
     - C:/Ruby187/lib/ruby/gems/1.8
     - C:/Documents and Settings/zeljko/.gem/ruby/1.8
  - GEM CONFIGURATION:
     - :update_sources => true
     - :verbose => true
     - :benchmark => false
     - :backtrace => false
     - :bulk_threshold => 1000
  - REMOTE SOURCES:
     - http://rubygems.org/

When I try to install watir-webdriver gem, I get this error message:

C:\Documents and Settings\zeljko>gem install watir-webdriver
ERROR:  While executing gem ... (ArgumentError)
    marshal data too short

I am searching around, but did not find the solution yet.

Answer 1

jarib suggested I should delete .gem folder (C:\Documents and Settings\zeljko\.gem) and it fixed the problem.