Difference in ASIO output plugin for FB2K & Winamp

[I have a SB Audigy with driver v5.12.5.441 dated 10/21/03. These are the latest official drivers you can get from Creative’s web site.]

With Otachan’s ASIO output plug-in v0.44b for Foobar2000, I can only get it to ouput to 16 bit depth.  Trying any other output bit depth will give me this error:

INFO (foo_output_asio(dll)) : open : 48000 Hz, LINEAR PCM, 24 bits, 2 channels
INFO (foo_output_asio(dll)) : ASIO device type [channel 0] : Int16LSB
INFO (foo_output_asio(dll)) : ASIO device type [channel 1] : Int16LSB
ERROR (foo_output_asio(dll)) : unsupported output data format.

However, I also use the Winamp ASIO output plug-in v0.52 by Otachan.  In conjunction with Shibatch’s mpg123 input plug-in, I can use up to 32 bit depth (int). 

Is the Winamp ASIO plug-in converting back down to 16 bit depth automatically?  If so, why doesn’t the Foobar2K plug-in not do this?  If not, then what exactly is being output by Winamp???

I’m confused.