R error in melt (reshape) - number of rows
===

Have a look at this test data set with five observations and two factor variables.

    test
    
      respid                  s2q1                      s2q2
    1     32                     9          5 - V. satisfied
    2     35       10 - Definitely          5 - V. satisfied
    3    148       10 - Definitely          5 - V. satisfied
    4    371                     3                         2
    5    416       10 - Definitely          5 - V. satisfied


When I run the following `melt` command, I get an error that doesn't make sense to me. Especially, because I've used the same commands before successfully.

    require(reshape2)
    qhist <- melt(test, id="respid")

    Error in data.frame(ids, variable, value, stringsAsFactors = FALSE) : 
      arguments imply differing number of rows: 5, 10