Philips DVP642/37

I have had this player for a few years now, and for the most part iv been pretty happy with it. I have only had a few minor problems with it, im here today to see if anyone can help me solve them. Firstly i am having a few issues with subtitles. Sometimes when i burn a .sub file and load it on the dvd player they show up as "?" marks, other times the dvp642 thinks that they are mpeg files? Any idea what could be causing the player to think these files are other formats? Another issue is the fact that when i play some flicks the picture shows up all blocky w/ neon colors as if the player doesnt have the right codec. When i hit the system menu button on the remote twice it clears the picture right up, although skipping ahead a few seconds in the process, it gets the job done. On rare occasions doing this will desynch the audio. Anyways what could be causing this? I have never upgraded my firmware, and i was wondering if doing so would fix other of these inconveniences? If so, which is the newest firmware/software available for the Philips DVP 642/37? Any help would greatly be appreciated.
-Joey T.

Edit::: my current firmware reads, "Ver1223 642/37 01 E1

I updated the firmware with the only one that Philips had on thier website and it made mine to where it would only read fatory pressed DVDs .

Here is an interesting find for u guys: http://forum.doom9.org/showthread.php?s=&threadid=93330
The dude in the forum claims that fw will work for 642. Let me know if it does. That dvp630_05 seems to be the latest.

Did you ever find a fix for this? I am now having the exact same issue with the pixelation with certain avi's. They all play find on my cpu, but when I burn them as a data disk, some play fine, and some are pixelated. It's like a crap shoot now.