[Optimus One, P500 Original Android Development] d3s3rt_eagle:
I think it's a MediaServer problem, logcat reports the same errors using browser or youtube app... Here it is:

E/msm7x27.gralloc( 156): [1] state A, expected S
W/AudioFlinger( 3450): session id 4 not found for pid 156
E/libEGL ( 2946): call to OpenGL ES API with no current context (logged once per thread)
D/MediaPlayer( 2946): Couldn't open file on client side, trying server side
I/AwesomePlayer( 3450): setDataSource_l('http://o-o.preferred.seabone-mil1.v16.lscache2.c.youtube.com/videoplayback?el=home&begin=0&yms=5OXcMcQa1IU&dnc=1&itag=18&ip=79.0.0.0&app=youtube_mobile&signature=A656C614146ECB25AB242A1B2C90347F95383D29.BB1F66B4451620D502C9598135DA00B5FF1CC90E&sparams=id%2Cexpire%2Cip%2Cipbits%2Citag%2Csource%2Cratebypass%2Ccp&len=574000&ratebypass=yes&source=youtube&expire=1327701837&sver=3&key=yt1&ipbits=8&cp=U0hRTFdLT19IUUNOMV9PRVNJOjBMV2FQZk14N0hY&id=2f35fbfe73d983a4')
F/HTTPBase( 3450): frameworks/base/media/libstagefright/HTTPBase.cpp:52 Should not be here.
F/libc ( 3450): Fatal signal 11 (SIGSEGV) at 0xdeadbaad (code=1)
D/dalvikvm( 310): GC_CONCURRENT freed 388K, 36% free 7400K/11463K, paused 4ms+5ms
I/DEBUG ( 3449): *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
I/DEBUG ( 3449): Build fingerprint: 'LGE/thunderg/thunderg:4.0.3/MR1/eng.pasquale.20120127.112715:user/test-keys'
I/DEBUG ( 3449): pid: 3450, tid: 3457 >>> /system/bin/mediaserver <<<
I/DEBUG ( 3449): signal 11 (SIGSEGV), code 1 (SEGV_MAPERR), fault addr deadbaad
I/DEBUG ( 3449): r0 deadbaad r1 0000000c r2 00000027 r3 a0000000
I/DEBUG ( 3449): r4 00000000 r5 00000080 r6 00080000 r7 00000008
I/DEBUG ( 3449): r8 41128000 r9 40b08709 10 00100000 fp 000142a4
I/DEBUG ( 3449): ip ffffffff sp 41227990 lr 4005ee6f pc 4005b622 cpsr 00000030
I/DEBUG ( 3449): d0 0000000000000000 d1 0000000000000000
I/DEBUG ( 3449): d2 7e37e43c8800759c d3 0000000000000000
I/DEBUG ( 3449): d4 0000000000000000 d5 7e37e43c8800759c
I/DEBUG ( 3449): d6 3ff0000000000000 d7 3ff0000000000000
I/DEBUG ( 3449): d8 0000000000000000 d9 0000000000000000
I/DEBUG ( 3449): d10 0000000000000000 d11 0000000000000000
I/DEBUG ( 3449): d12 0000000000000000 d13 0000000000000000
I/DEBUG ( 3449): d14 0000000000000000 d15 0000000000000000
I/DEBUG ( 3449): scr 20000000
I/DEBUG ( 3449):
I/DEBUG ( 3449): #00 pc 00017622 /system/lib/libc.so
I/DEBUG ( 3449): #01 pc 000015fc /system/lib/liblog.so (__android_log_assert)
I/DEBUG ( 3449):
I/DEBUG ( 3449): code around pc:
I/DEBUG ( 3449): 4005b600 1c2bd00c 2d00682d e027d1fb 2a0068da ..+.-h.-..'..h.*
I/DEBUG ( 3449): 4005b610 4b16d004 447b2001 47906018 22274814 ...K. {D.`.G.H'"
I/DEBUG ( 3449): 4005b620 70022580 ef96f7f4 f7f62106 aa01e816 .%.p.....!......
I/DEBUG ( 3449): 4005b630 05692400 60546091 20061c11 f7f59401 .$i..`T`... ....
I/DEBUG ( 3449): 4005b640 a905ebf0 20022200 ebf8f7f5 ef82f7f4 .....". ........
I/DEBUG ( 3449):
I/DEBUG ( 3449): code around lr:
I/DEBUG ( 3449): 4005ee4c 4b0db5f0 447bb083 681c2600 68a59001 ...K..{D.&.h...h
I/DEBUG ( 3449): 4005ee5c e0086867 5ea8220c dd032800 99011c28 gh...".^.(..(...
I/DEBUG ( 3449): 4005ee6c 43064788 3f013554 6824d5f4 d1ee2c00 .G.CT5.?..$h.,..
I/DEBUG ( 3449): 4005ee7c 1c30b003 46c0bdf0 00028692 1c0fb5f0 ..0....F........
I/DEBUG ( 3449): 4005ee8c b0891c3d a9064355 604d9103 90064914 =...UC....M`.I..
I/DEBUG ( 3449):
I/DEBUG ( 3449): memory map around addr deadbaad:
I/DEBUG ( 3449): bec2e000-bec4f000 [stack]
I/DEBUG ( 3449): (no map for address)
I/DEBUG ( 3449): (no map above)
I/DEBUG ( 3449):
I/DEBUG ( 3449): stack:
I/DEBUG ( 3449): 41227950 00000000
I/DEBUG ( 3449): 41227954 000003b7
I/DEBUG ( 3449): 41227958 40087720 /system/lib/libc.so
I/DEBUG ( 3449): 4122795c 400876b0 /system/lib/libc.so
I/DEBUG ( 3449): 41227960 00000000
I/DEBUG ( 3449): 41227964 4005ee6f /system/lib/libc.so
I/DEBUG ( 3449): 41227968 00000009
I/DEBUG ( 3449): 4122796c 4005dbd5 /system/lib/libc.so
I/DEBUG ( 3449): 41227970 400411cd /system/lib/liblog.so
I/DEBUG ( 3449): 41227974 00000000
I/DEBUG ( 3449): 41227978 00000000
I/DEBUG ( 3449): 4122797c 00080000
I/DEBUG ( 3449): 41227980 00000008
I/DEBUG ( 3449): 41227984 4005dfed /system/lib/libc.so
I/DEBUG ( 3449): 41227988 df0027ad
I/DEBUG ( 3449): 4122798c 00000000
I/DEBUG ( 3449): #00 41227990 4122798c
I/DEBUG ( 3449): 41227994 00000001
I/DEBUG ( 3449): 41227998 40b819e5 /system/lib/libstagefright.so
I/DEBUG ( 3449): 4122799c 00000009
I/DEBUG ( 3449): 412279a0 412279c4
I/DEBUG ( 3449): 412279a4 fffffbdf
I/DEBUG ( 3449): 412279a8 00000000
I/DEBUG ( 3449): 412279ac 40b819e5 /system/lib/libstagefright.so
I/DEBUG ( 3449): 412279b0 00014290 [heap]
I/DEBUG ( 3449): 412279b4 400415ff /system/lib/liblog.so
I/DEBUG ( 3449): #01 412279b8 40b819e5 /system/lib/libstagefright.so
I/DEBUG ( 3449): 412279bc 400415ff /system/lib/liblog.so
I/DEBUG ( 3449): 412279c0 41227dd4
I/DEBUG ( 3449): 412279c4 6d617266
I/DEBUG ( 3449): 412279c8 726f7765
I/DEBUG ( 3449): 412279cc 622f736b
I/DEBUG ( 3449): 412279d0 2f657361
I/DEBUG ( 3449): 412279d4 6964656d
I/DEBUG ( 3449): 412279d8 696c2f61
I/DEBUG ( 3449): 412279dc 61747362
I/DEBUG ( 3449): 412279e0 72666567
I/DEBUG ( 3449): 412279e4 74686769
I/DEBUG ( 3449): 412279e8 5454482f
I/DEBUG ( 3449): 412279ec 73614250
I/DEBUG ( 3449): 412279f0 70632e65
I/DEBUG ( 3449): 412279f4 32353a70
I/DEBUG ( 3449): 412279f8 6f685320
I/DEBUG ( 3449): 412279fc 20646c75
I/BootReceiver( 156): Copying /data/tombstones/tombstone_09 to DropBox (SYSTEM_TOMBSTONE)
W/AudioSystem( 2946): AudioFlinger server died!
W/IMediaDeathNotifier( 2946): media server died
E/MediaPlayer( 2946): error (100, 0)