virtualdub only capturing 1 field from my vcr

[lansing]

I'm trying to capture my old tape from a vcr to pc, the device I'm using is easycap. The preview resolution is fine 640x480. but when i click capture, the preview window is showing 2 fields like the picture, and the output file is 640x240 with only 1 field.
What am I doing wrong?

http://img27.imageshack.us/img27/8159/captureyvre.jpg

[lansing]

nvm, i found out the problem, i checked the vertical reduction option thats why it's only showing half screen