Advice on popping noise from Audio Aero Prestige

I recently upgraded this player to 'signature edition' (cryo tubes, exotic caps, better damping). Sounds brilliant and is an improvement over standard unit. Upgrade took place at factory in France.

Popping noises (esp on left channel) now occurs whenever volume is changed, pressing stop, or choosing next/previous track. Also, player gets confused on repeat play (at end of cd/sacd it either stops or goes into scan mode). When system is idle, a buzzing sound comes through left channel. However, when playing music none of these noises occur.

Prior to upgrade, no such problems happened. My dealer suggests that I should burn-in the player for longer in the hope that popping and buzzing significantly reduces. I'm not entirely convinced this will work and seek other suggestions/solutions. Also, is it safe to continue using this player?

Thanks in advance.