USPS international shipping calculation problem

I have Zen Cart 1.3.9h installed and the web site (orionsattic.com) has been up an running with one problem: international shipping calculation.

No problem with domestic shipping but once the shipping address is indicated as abroad other than the US, the below error message pops up for USPS and only UPS expedited service (which ends up with astronomical shipping cost) is available.

Message from the USPS section on the shipping screen*
We are unable to find a USPS shipping quote suitable for your mailing address and the shipping methods we typically use.
If you prefer to use USPS as your shipping method, please contact us for assistance. (Please check that your Zip Code is entered correctly.)

So I turned on receiving debugging email and have got the below message. which I have no idea where the error is occurring. I saw some message threads regarding a similar issue with 1.3.8 but it sounds like it's been resolved and I don't see any issue with the current version. Can anybody help me? I appreciate in advance.

<RateV3Response><Package ID="0"><ZipOrigination>20024</ZipOrigination><ZipDestination>20032</ZipDestination><Pounds>6</Pounds><Ounces>8</Ounces><Container></Container><Size>REGULAR</Size><Zone>1</Zone><Postage CLASSID="3"><MailService>Express Mail^&reg;</MailService><Rate>26.35</Rate></Postage></Package><Package ID="1"><Error><Number>-2147219434</Number><Source>DomesticRatesV3;clsRateV3.ValidateWeight;RateEngineV3.ProcessRequest</Source><Description>First Class mail must weigh 13 ounces or less.</Description><HelpFile></HelpFile><HelpContext>1000440</HelpContext></Error></Package><Package ID="2"><ZipOrigination>20024</ZipOrigination><ZipDestination>20032</ZipDestination><Pounds>6</Pounds><Ounces>8</Ounces><Container></Container><Size>REGULAR</Size><Zone>1</Zone><Postage CLASSID="1"><MailService>Priority Mail^&reg;</MailService><Rate>9.30</Rate></Postage></Package></RateV3Response>

Have you checked the threads in the Similar Threads section near the bottom of this page?

Oh, thank you for reminding again. My initial search was not thorough enough so I didn't realize the solution proposed applies to the new version 1.3.9h as well. After your advice, I went through these threads again, and followed the instruction from the below thread #27 and fixed the problem. Thank you!

http://www.zen-cart.com/forum/showthread.php?t=171314