amd64 + bttv = не работает [solved]

именно не работает. были бы сообщения об ошибках - думаю разобрался бы...
точно также сделано в gentoo-i686 на этой же машине. работает.
вот что пишет dmesg | grep tv на amd64

bttv: driver version 0.9.16 loaded
bttv: using 8 buffers with 2080k (520 pages) each for capture
bttv: Bt8xx card found (0).
bttv0: Bt878 (rev 17) at 0000:02:08.0, irq: 18, latency: 32, mmio: 0xfdeff000
bttv0: using: Prolink Pixelview PV-BT878P+ (Rev.4C,8E) [card=70,insmod option]
bttv0: gpio: en=00000000, out=00000000 in=00ffc0ff [init]
bttv0: using tuner=25
bttv0: i2c: checking for MSP34xx @ 0x80... not found
bttv0: i2c: checking for TDA9875 @ 0xb0... not found
bttv0: i2c: checking for TDA7432 @ 0x8a... not found
bttv0: i2c: checking for TDA9887 @ 0x86... not found
bttv0: registered device video0
bttv0: registered device vbi0
bttv0: registered device radio0
bttv0: PLL: 28636363 => 35468950 .<4>nvidia: module license 'NVIDIA' taints kernel.
input: bttv IR (card=70) as /class/input/input4

пульт работает - cat /dev/input/event4 подает признаки жизни...

а вот на i686 (32bit):

bttv: driver version 0.9.16 loaded
bttv: using 8 buffers with 2080k (520 pages) each for capture
bttv: Bt8xx card found (0).
bttv0: Bt878 (rev 17) at 0000:02:08.0, irq: 20, latency: 32, mmio: 0xfdeff000
bttv0: using: Prolink Pixelview PV-BT878P+ (Rev.4C,8E) [card=70,insmod option]
bttv0: gpio: en=00000000, out=00000000 in=00ffc0ff [init]
bttv0: using tuner=25
bttv0: i2c: checking for MSP34xx @ 0x80... not found
bttv0: i2c: checking for TDA9875 @ 0xb0... not found
bttv0: i2c: checking for TDA7432 @ 0x8a... not found
bttv0: i2c: checking for TDA9887 @ 0x86... not found
bttv0: registered device video0
bttv0: registered device vbi0
bttv0: registered device radio0
bttv0: PLL: 28636363 => 35468950 .. ok
input: bttv IR (card=70) as /class/input/input4

т.е. карта инициализируется нормально в обоих случаях

вот что пишет tvtime -v на i686

Running tvtime 1.0.2.
Reading configuration from /etc/tvtime/tvtime.xml
Reading configuration from /home/andrew/.tvtime/tvtime.xml
cpuinfo: CPU AMD Athlon(tm) 64 Processor 3000+, family 15, model 12, stepping 2.
cpuinfo: CPU measured at 2009,324MHz.
tvtime: Cannot set priority to -10: Отказано в доступе.
xcommon: Display :0.0, vendor The X.Org Foundation, vendor release 70200000
xfullscreen: Single-head detected, pixel aspect will be calculated.
xfullscreen: Pixel aspect ratio on the primary head is: 1328/1205 == 1,10.
xfullscreen: Using the XFree86-VidModeExtension to calculate fullscreen size.
xfullscreen: Fullscreen to 0,0 with size 1280x1024.
xcommon: Have XTest, will use it to ping the screensaver.
xcommon: Pixel aspect ratio 1:1.
xcommon: Pixel aspect ratio 1:1.
xcommon: Window manager is KWin and is EWMH compliant.
xcommon: Using EWMH state fullscreen property.
xcommon: Using EWMH state above property.
xcommon: Using EWMH state below property.
xcommon: Pixel aspect ratio 1:1.
xcommon: Displaying in a 768x576 window inside 768x576 space.
xvoutput: Using XVIDEO adaptor 326: NV17 Video Texture.
speedycode: Using MMXEXT optimized functions.
station: Reading stationlist from /home/andrew/.tvtime/stationlist.xml
videoinput: Using video4linux2 driver 'bttv', card 'BT878 video (Prolink Pixelview ' (bus PCI:0000:02:08.0).
videoinput: Version is 2320, capabilities 5010015.
videoinput: Maximum input width: 924 pixels.
tvtime: Sampling input at 768 pixels per scanline.
xcommon: Pixel aspect ratio 1:1.
xcommon: Displaying in a 768x576 window inside 768x576 space.
xcommon: Received a map, marking window as visible (70).
tvtime: Cleaning up.
Thank you for using tvtime.

работает. кажет.

вот на amd64:

Running tvtime 1.0.2.
Reading configuration from /etc/tvtime/tvtime.xml
Reading configuration from /home/andrew/.tvtime/tvtime.xml
cpuinfo: CPU AMD Athlon(tm) 64 Processor 3000+, family 15, model 12, stepping 2.
cpuinfo: CPU measured at 2009,553MHz.
tvtime: Cannot set priority to -10: Отказано в доступе.
xcommon: Display :0.0, vendor The X.Org Foundation, vendor release 70200000
xfullscreen: Single-head detected, pixel aspect will be calculated.
xfullscreen: Pixel aspect ratio on the primary head is: 1328/1205 == 1,10.
xfullscreen: Using the XFree86-VidModeExtension to calculate fullscreen size.
xfullscreen: Fullscreen to 0,0 with size 1280x1024.
xcommon: Have XTest, will use it to ping the screensaver.
xcommon: Pixel aspect ratio 1:1.
xcommon: Pixel aspect ratio 1:1.
xcommon: Window manager is KWin and is EWMH compliant.
xcommon: Using EWMH state fullscreen property.
xcommon: Using EWMH state above property.
xcommon: Using EWMH state below property.
xcommon: Pixel aspect ratio 1:1.
xcommon: Displaying in a 768x576 window inside 768x576 space.
xvoutput: Using XVIDEO adaptor 325: NV17 Video Texture.
speedycode: Using MMXEXT optimized functions.
station: Reading stationlist from /home/andrew/.tvtime/stationlist.xml
videoinput: Using video4linux2 driver 'bttv', card 'BT878 video (Prolink Pixelview ' (bus PCI:0000:02:08.0).
videoinput: Version is 2320, capabilities 5010015.
videoinput: Maximum input width: 924 pixels.
tvtime: Sampling input at 768 pixels per scanline.
xcommon: Pixel aspect ratio 1:1.
xcommon: Displaying in a 768x576 window inside 768x576 space.
xcommon: Received a map, marking window as visible (62).

иногда показывает канал, который был последним на i686. обычно - синий фон. каналы не переглючает, хотя нумерацию показывает. и ошибок не выдает, т.е. считает, что все нормально.
тоже самое с kdetv - при первом запуске пытается настроиться (т.е. карточка для него доступна).
права в /dev/v4l/* и симлинках проверял.
Т.Е. явных ошибок нет... Но не работает...