title: Getting NA for join values - left_join() in dplyr package
body: <p>I'm new to the dplyr package and trying on a <code>join</code> operation for two data frames. </p>
  
  <p>The data is as follows</p>
  
  <pre><code>&gt; overview
  Source: local data frame [972 x 14]
  
         household                        names  x2003  x2004  x2005  x2006  x2007  x2008  x2009  x2012 last.avail last.avail.year absChange.last annChange.last
             (chr)                       (fctr)  (int)  (int)  (int)  (int)  (int)  (int)  (int)  (int)      (int)           (dbl)          (int)          (dbl)
  1  single parent            totala utgifterna 215300 219870 241920 241060 229290 253590 255950 277260     277260            2012          61960     0.02850119
  2  single parent              köpta livsmedel  26420  27910  28160  29100  28310  33020  35910  33740      33740            2012           7320     0.02754621
  3  single parent     bröd, spannmålsprodukter   4760   5770   4940   5360   5070   5830   6310     NA       6310            2009           1550     0.04810245
  4  single parent     ris och produkter av ris    240    290    210    230    220    280    420     NA        420            2009            180     0.09775732
  5  single parent                          ris    100     70     70    130    110    180    200     NA        200            2009            100     0.12246205
  6  single parent                 risprodukter    140    220    130    100    120    100    220     NA        220            2009             80     0.07824083
  7  single parent pasta och produkter av pasta    410    450    370    460    580    490    600     NA        600            2009            190     0.06551908
  
  &gt; translation
  Source: local data frame [8 x 2]
  
              translation                                   household
                   (fctr)                                      (fctr)
  1          Accomodation                                      bostad
  2   Leisure and culture                           fritid och kultur
  3        Transportation                                   transport
  4      Bought Groceries                             köpta livsmedel
  5 Rent for accomodation hyra/avgift för hyres-/borätt (inkl garage)
  6    Household services                            hushållstjänster
  7           Rents (net)                             räntor (brutto)
  8          Car expenses                                drift av bil
  </code></pre>
  
  <p>Now when I run <code>left_join(overview, translation)</code> I get the following result. </p>
  
  <pre><code>&gt; left_join(overview, translation)
  Joining by: "household"
  Source: local data frame [972 x 15]
  
         household                        names  x2003  x2004  x2005  x2006  x2007  x2008  x2009  x2012 last.avail last.avail.year absChange.last annChange.last translation
             (chr)                       (fctr)  (int)  (int)  (int)  (int)  (int)  (int)  (int)  (int)      (int)           (dbl)          (int)          (dbl)      (fctr)
  1  single parent            totala utgifterna 215300 219870 241920 241060 229290 253590 255950 277260     277260            2012          61960     0.02850119          NA
  2  single parent              köpta livsmedel  26420  27910  28160  29100  28310  33020  35910  33740      33740            2012           7320     0.02754621          NA
  3  single parent     bröd, spannmålsprodukter   4760   5770   4940   5360   5070   5830   6310     NA       6310            2009           1550     0.04810245          NA
  4  single parent     ris och produkter av ris    240    290    210    230    220    280    420     NA        420            2009            180     0.09775732          NA
  5  single parent                          ris    100     70     70    130    110    180    200     NA        200            2009            100     0.12246205          NA
  6  single parent                 risprodukter    140    220    130    100    120    100    220     NA        220            2009             80     0.07824083          NA
  </code></pre>
  
  <p>As you can see, all the translations are of NA values. On for example index number <code>[2, 'names']</code> translation should equal "Bought groceries" but it doesn't. </p>
  
  <p>What has happened and how can this be fixed? </p>