wmcodec.exe well encodes in WMA 9.1, WMA 9.1 Professional, WMA 9.1 Lossless, but badly encodes in WMA 9.2, WMA 10 Professional, WMA 9.2 Lossless.
wav 1 h 28 min 58 sec - wma 9.1 1 h 28 min 58 sec
wav 1 h 28 min 58 sec - wma 9.2 1 h 36 min 50 sec !!!