Thanks for your reply.
I tried both ways. Equal result.
The last time I chose to install via the utility and marked that I'd like it to NOT use a cached version, in other words, download a fresh one. Should be the proper one I reckon.
In addition to my initial post, I found that using the original firmware (2.10e) results in scribbling sounds in any audio file (mp3 - vbr + cbr, wav, ...) as if decoding has errors, presumably while buffering from HD to flash (always at the start of playing or skipping, sometime during play).
Does this clarify?