I originally wanted to use the Roku in wifi mode, but I found that every few minutes, the Roku would keep re buffering. You could not listen to the music under those conditions.
I initially used the Roku's supplied wifi "Card" then changed to a DLink Ethernet/ wifi transmitter/reciever (similar to DWL-G820 ).
I had this in perfect line of sight about 3M seperation and still the Roku buffered.
If I access a MP3 file there was no problem (other then I didn't like the sound quality), there was no buffering.
When I replaced the wifi link with a direct ethernet link there was no buffering.
Now because:
1.MP3 files (as you know) are much smaller then the fuller .wav files.
2. Roku buffered when ethernet/wifi link was used (and not when the pure ethernet link was used).
I concluded that the wifi link was not upto it.
Incidentally I got no drop outs with MP3 or internet radio
I know the latest firmware for Roku is supposed to be able to use apple lossless natively, but I have been "warned" off doing that be the number of people saying apple lossless sounds inferier ( despite it being lossless- no I don't understand that either). I don't fancy recoding all my Flac files to find later on that I don't like the quality.