[Icom] PSK31 and sound card question.

[icom@mailman.qth.net]

I use a compaq PC with a built in sound chip ESS Technologies ES1869F.
It is supposed to run of a 14.31818Mhz clock. When I measured the clock 
input to the sound chip I measured 14.31954Mhz using a frequency counter.

The problem I have is, I have garbled text displayed even on strong signals.

How important is the clock frequency accuracy for receiving PSK31?
The clock on this board is difficult to tell where it is generated as I can not
find any 14.318  crystal oscillator. I'm tempted to unsolder the X0/X1 sound chip
clock input/output pins and build an off board crystal oscillator with
higher precision. 

Any info on this would be helpful. (Other than buying another computer (i.e. non Compaq)).

Regards,
John
K1JEB