I recently installed the latest firmware update for both my LG BD530 and BD550 players:

File: LG_BD_5200M50.ROM
MAIN VER: BD5.279.00
DATE: 2013.03.06

It has created two new problems that I never had before when playing MKV files:

PROBLEM 1: 3/5 times playback and player will freeze as soon as subtitles are supposed to show up. I only use SRT or SSA, both supported by the player as per user manual. The freeze is so bad that the player won’t even turn off. I have to cut the power feed off then turn it back on so I can restart the player.

PROBLEM 2: multi-channel audio signals (mainly DD and DTS) are not being properly passed to my home theater receiver via HDMI connection. There are simply NO surround signals being decoded at all. My audio setting for both players is Primary Pass-Thru and it has always worked perfectly for absolutely every media I've ever played (DVD, BD, MKV, MP4, etc), up until now.

I went and rolled back the firmware to the previous version I had installed:

File: LG_BD_5200M50.ROM
MAIN VER: BD5.279.00
DATE: 2013.01.16

It solved Problem 2, surround signals are again passed and decoded properly, but Problem 1 remains: MKV files will play fine if no subtitles are selected, but playback and player will freeze when subtitles are on (not always, but most times). And yes, I'm just realizing that this FW version was also borked all along, but all this time I thought it was my old USB flash drive at fault. Then I tested a brand-new USB flash drive, same problem. It is only now after some research that I'm finding out that it is in fact a firmware issue.

Unfortunately, I have no other previous firmware versions stored. Any BD530/550 owners out there who, by any chance, kept all their FW update files that would give me a link to download it from?

Please help! Thanks.