1006
The compressed data passed to the Uncompress method was successfully uncompressed by the compression engine and passed the CRC test, however, not all the compressed data was used in order to produce the uncompressed output. In other words, the decompression engine expected less data than the amount passed to it.
Either too much data is being passed to the Uncompress method (you are providing extra, unnecessary data after the compressed data) or the data may possibly be corrupted (although this latter possibility is unlikely due to the checksum verification step).