I have also a lot of problems with my NP3900. I stream with my Synology NAS by WLAN to the player. Sometimes everything is ok, but often my player stucks in standby or lose the wlan connection! Then I can also only restart the player!
Where are hiding the mods? What is your alternate product?
Got update G5.72S for NP3900 installed yesterday. No clue what's new/what's not, except Napster seems to be enabled again. Device is connected via wire to LAN, gets music via DLNA from QNAP/Twonky server. After about 1 hour of listening to music (no other interventions or RC commands), device suddenly gave plop, white screen with vertical bars, no reaction to any command (RC, local keyboard). Unplug power is only way to restart => new firmware still no solution to stability problems.
I took my radio outlook retirement and tried the new firmware. Waste of time. Pity there was no way to hack it and install different firmware.
I am very happy with my 42" Philips TV bought 4 yrs ago but Streamium is an embarrassment. Philips technology designers should hang their heads in shame.