Crackling at start of playback!!

[Memphis102]

Odd and inexplicable behaviour. My two Fuze+ with RockBox builds had been working perfectly until recently... then suddenly both of them started to exhibit a strange crackling sound on the beginning of playback. After a few seconds this disappears. Similar crackling noise can be heard when pressing buttons, but not to the same extent. The only thing I could think of that was common to both was the headphones... but swapped those out and the problem remains. The only other common thing I can think of is.. me. I have tried rebooting into Sansa Firmware but for some reason it stays stuck at the 'Loading' screen. Any thoughts, anyone?