venkat..u c i earlier(feb-march 2011) had a samsung 40c530 Lcd tv(a step lower model than the d550 in question) for about a month & half...until i returned the tv,but within that timeframe,i got to playback all sort of sd/hd/fhd videos along with allmost everytype of external subtitles & if my memory doesnot betray me,all of those videos alongwith the all type of subtitles were displayed perfectly .Now after another 2-3 month,i got again another samsung,this time a 51" plasma d550 & i am really pleased to tell you that the samsung plays all sort of videos i have thrown at it(through it's usb ports) along with subtitles & .dts audio with equal aplomb & morever the 2011 d series r better at displaying subtitles(have even more options).To state hard facts,the samsung tv integrates a VERY GOOD mediaplayer & u can skip purchasing a dedicated media player alltogether,if u r short on ur budget!...it even surpasses my PCH in media compatibility & subttile playback.
Now,afaik samsung is doing a top notch job in this usb playback dept.for all their tvs across the range from lcd/lcd-led's to their big plasmas since 2009 launches & also going by my own personal experiences from my two samsung tv,i'm more than sure that the 32d550 would surely playback all media/videos alongwith subtitle with perfection!
comparing with samsung which is even priced lesser for comparitive models & offers more vfm,..sony appears more stingy & less user friendly in providing features that would have made their tv owners more happy....i think Sony doesnot care & r too overconfident to sell alone by brand value of the monicker on their tv,which most common mango ppl makes their priority while purchasing their tv! i ain't saying sony tvs r bad, but if they dont pay due attention to customer needs,they would surely generate lot of bad sales & genuinely upsetting their valuable(?)customers!