Hi,
It indeed seems there are some bad clones out there regarding audio capturing.
I bought my EasyCAP faily cheap, strangely there was no Ulead video capture on the yellow cd but an Honestech proggy that captures video/audio in maximum 4G blocks.
Anyway I have Ulead now installed and started capturing.
My EasyCAP seems to pick up a bad 50Hz buzz.
Luckly you can select your mic source and by bypassing it and using an headset mic am am getting much better results, i have also tried to gab the sound with my audio PC card and that work great as well.
It will do it trick as I need only a couple of VHS tapes (mono sound anyway) to be captured.
Hope my solution helps maybe someone else.

Cheers,
Bruskii