Sounds playback in only one speaker

[liquidmusic]

I downloaded Goldwave, its very good. However
my sound only comes out of one speaker. Here is how I have it set up.

Cassette deck line out is connected to my
line in sound card. My pc speakers are plug in as usual to the out line for speakers.
I get a ver good playback recording, no
distortion at all except for one speaker
playing.
At first I had the cassette lineout going to
the soundcard "mic" input but there was way too much distortion even though I adjusted everything to very low.
What am I doing wrong? And does this mean
if I burn a cd and I go to play it in any other cd player, will sound go through only
one speaker. I am so confused!!! Appreciate
anyones help.