It looks like the page is adding too many decimals when passing the amounts to paypal. If you send me your confirm.php page I can tell you the lines to update in that one. On the pp_confirm you would update line 97 to:
$WA_PP_ECO_Do_itemized[1][0] = "".number_format($eCart1->GrandTotal(),2) ."";
update line 103 to: $WA_PP_ECO_Do_itemized[1][$nextIndex] = "".number_format($eCart1->DisplayInfo("Price"),2) ."";
and update line 132 to: $WA_PP_ECO_Do_optional[1][$nextIndex] = "".number_format($eCart1->TotalColumn("TotalPrice"),2) ."";
All I'm doing is finding the dollar values and using number_format() to make sure they only pass two decimals. You could probably find the same three lines on your confirm page without me, but if you send it to me I can tell you directly.