[R] ctree question

[seanstclair at verizon.net]

   Hello.  I have used the "party" package to generate a regression tree as
   follows:

   >origdata<-read.csv("origdata.csv")
   >ctrl<-ctree_control(mincriterion=0.99,maxdepth=10,minbucket=10)
   >test.ct<-ctree(Y~X1+X2+X3,data=origdata,control=ctrl)

   The above works fine.  Orig data was my training data.  I now have a test
   data file (testdata), and would like to run the testdata through the above
   tree to see predictions.  I tried using the following function

   >predict(test.ct,newdata=testdata)

   but I get the following error:

   Error in checkData(oldData, RET) :
     Levels in factors of new data do not match original data
    
   I've looked at the testdata file closely and it does not appear to contain
   any levels of factors that were not in the original.  What might I be doing
   incorrectly, and how can i use the tree that was generated above to generate
   predictions for this new file testdata?
   
   THanks.
   sean