I am also having this error, it started suddenly yesterday. When ever I set the stream to higher than 160x120, I get a message - 'The operation can not be performed as the pins are not connected'.
I haven't changed anything on the pc between when it was working and yesterday
Its really annoying as I have tried reinstalling the webcam driver, but get the same error. I have also searched the internet, trying many solutions without success. I also ran the windows restore, again without success. Nothing else is using the webcam as I checked with process explorer.
It was working very smooth in euro truck 2 for a few weeks with 320x240 and now its too 'jumpy' to use with the lower resolution.
Thanks
Edit:
Forgot to mention I am using a ps2 eyetoy and windows 8.1