ngram-count and float counts

[Daniel Walker]

I'm trying to create a back-off file using ngram-count and a count file that 
has float "counts" derived from another model but get the error message:

error in discount estimator for order 1

The -float-counts option says that it only supports certain types of 
discounting but doesn't say which. Could this be the problem? Otherwise, what 
sort of data problems could cause this message, does anyone know?

Thanks,

Dan