My Hauppauge WINPVR150 has been configured perfectly with the right ivtv drivers and firmware, I'm able to watch television, dmesg | grep ivtv is correct and so on. This is all in OpenSuse 10.3, my OS with KDE3.5, partly KDE4.

When I used Suse 10.1 I was able to switch to my s-vhs/s-video connection on my TV card under the following syntaxis:
# ivtvctl -d /dev/video0 -p 1 but see what happens now:
ivtvctl: invalid option -- p
Unknown argument `1'
Usage:
-d, --device <dev> use device <dev> instead of /dev/video0
-h, --help display this help message
-K, --passthrough <mode>
set passthrough mode: 1 = on, 0 = off [IVTV_IOC_PASSTHROUGH]
--get-yuv-mode display the current yuv mode
--set-yuv-mode [param],[param]
set the current yuv mode
param:
mode =<#> yuv_mode 0=interlaced,1=progressive,2=auto
threshold =<#> if src_hight <= threshold treat as progressive
--reset-ir reset the infrared receiver [VIDIOC_INT_RESET]
--version shows the version number of this utility.
It should match the driver version.

Expert options:
-D, --set-debug <level>
set the module debug variable
1: WARN 2: INFO 4: API 8: DMA
16: IOCTL 32: I2C 64: IRQ 128: DEC 256: YUV
-E, --end-gop capture last GOP [IVTV_IOC_S_GOP_END]
-e, --get-debug query the module debug variable
-I, --list-gpio
show GPIO input/direction/output bits
-i, --set-gpio [dir=<dir>,]val=<val>
set GPIO direction bits to <dir> and set output to <val>
-k, --sync test vsync's capabilities [IVTV_IOC_FRAMESYNC]
-R, --list-registers chip=<chip>,min=<addr>,max=<addr>
dump registers from <min> to <max> [VIDIOC_INT_G_REGISTER]
<chip> is one of: saa711x, saa7127, saa717x, cx2584x, cx2341x
-r, --set-register chip=<chip>,reg=<reg>,val=<val>
set register [VIDIOC_INT_S_REGISTER]
<chip> is one of: saa711x, saa7127, saa717x, cx2584x, cx2341x
-v, --audio-route=input=<in>,output=<out>
set the audio input/output routing [VIDIOC_INT_S_AUDIO_ROUTING]

Now when I changed this syntaxis into:
# ivtvctl -d /dev/video0 -K 1 I get the following:
ioctl IVTV_IOC_PASSTHROUGH failed: Invalid argument

I could not find anything about this problem in the release notes of OpenSuse 10.3.

What could be wrong, why I cannot switch from TV to s-video/s-vhs (connected, all cables are perfect) and back in OpenSuse 10.3.

Who's able to advice me? Thanks anyway.

I found the solution to this problem, reading ivtvdriver.org thoroughly.
From ivtv 0.8 all syntaxes are controlled by # v4l2-ctl, most of them are equal to the syntaxes normally used, but some of them are slightly different.
So connecting to your s-vhs/s-video on your TV-card, use the syntaxis: # v4l2-ctl -d /dev/video0 -i 1 and then link your /dev/video0 to mplayer/kmplayer or whatever and you will see that your conventional vhs recorder and possibly digital tv (those decoders have s-video out for TV-cards, TV-cards usually do not have a scart connection) and everything is working fine.
So e.g. this syntaxis and many others are controlled by # v4l2-ctl from ivtvdriver 0.8 and no longer by # ivtvctl (no specific Linux-distro meant).
Maybe some of you do know this, if not, I hope having advised the solution for other people with an equal problem properly.