Hello,
I am running latest Rockbox for Archos Recorder V1 (build from 14. December 2009). Whenever I try to play a WAV file, the screen with the informations of the WAV file just pops up shortly (e.g. Length: 3:24, Samplerate 44100, etc) and then closes one second later and I am back in the file-browser. No playback of the WAV starts. Not any WAV file I have on the player has ever played yet, though they are all 44,1Khz 16bit Stereo, from different sources (CD, downloaded, etc). So it can´t be a format-problem of a specific file. Since no WAV plays at all.
Btw, this was not just in the recent build, but in all rockbox builds I had on this player (starting middle of November).