2checkout parameter error

[coeus]

Hello,

When I am using the pm2checkout module, the latest version in contribs section. When I confirm checkout and get sent to 2checkout page I get this error:

QUOTE
Parameter Error


Incorrect parameters were supplied, therefore this purchase cannot begin.

If you are attempting to purchase from a web site please contact the web site so that they can correct the error.


Here are the values that get past:

CODE
<form onKeyUp="highlight(event)" onClick="highlight(event)" onKeyUp="highlight(event)" onClick="highlight(event)" name="checkout_confirmation" action="https://www2.2checkout.com/2co/buyer/purchase" method="post" onsubmit="return check_agree(this);">
<input type="hidden" name="c_prod_0" value="29,2">
<input type="hidden" name="sh_cost" value="15">
<input type="hidden" name="x_login" value="428603">
<input type="hidden" name="x_amount" value="7315.80">
<input type="hidden" name="x_invoice_num" value="20050928150047">
<input type="hidden" name="demo" value="Y">
<input type="hidden" name="fixed" value="Y">
<input type="hidden" name="id_type" value="2">
<input type="hidden" name="x_first_name" value="tester">
<input type="hidden" name="x_last_name" value="tester">
<input type="hidden" name="x_address" value="555 elm st">
<input type="hidden" name="x_city" value="555 Elm St">
<input type="hidden" name="x_state" value="Ontario">
<input type="hidden" name="x_zip" value="L5R 2T4">
<input type="hidden" name="x_country" value="Canada">
<input type="hidden" name="x_email" value="steve@overlee.com">
<input type="hidden" name="x_phone" value="555-555-5555">
<input type="hidden" name="x_ship_to_first_name" value="tester">
<input type="hidden" name="x_ship_to_last_name" value="tester">
<input type="hidden" name="x_ship_to_address" value="555 elm st">
<input type="hidden" name="x_ship_to_city" value="555 Elm St">
<input type="hidden" name="x_ship_to_state" value="Ontario">
<input type="hidden" name="x_ship_to_zip" value="L5R 2T4">
<input type="hidden" name="x_ship_to_country" value="Canada">
<input type="hidden" name="tco_currency" value="USD">
<input type="hidden" name="pay_method" value="CC">
<input type="hidden" name="x_email_merchant" value="TRUE">


I can't see what parameter is wrong? Can someone tell me what's wrong here, thanks