Question about MAX param size when calling StoredProc

Hi . I am using v0.82 of the freeTDS library. I am trying to call to call a
storedProc on a SQL2005 server that takes in a 'varbinary' field as input
paramter. The varbinary field is set up with '-1' as the Length in the
database. Here are the steps that I am doing.

1. Call dbrpcinit
2. Call dbrpcparam for each parameter
3. Call dbrpcsend
4. Call dbsqlok
5. Process all results with dbresults()


The problem that I am seeing is that for the 'varbinary' field; only 8000
chars are getting into the DB. Is that some sort of a limitation in FreeTDS?
Has anyone run into this particular issue before.

Thanks!