Error while sending XML to UPS

Hello, I have searched the forum to see if anyone had gotten this code when adding the first item to the shopping cart. I saw some XML error codes but none matched this one,

Error while sending XML to UPS. Error code: 10002. Message: The XML document is well formed but the document is not valid

No shipping method found

I have manipulated my UPS Plugin, Product weight and volume. I have not a clue where the prob is so, any help would be truly appreciated.
Thanks,
Charles

Nicholas,
I seem to be having unusual problem with the check out process. The previous problem seems to be cleared up.

My latest error state "The cart items combined volume is too big for all the possible shipping methods- Weight OR volume not found for the products in your cart" I have looked at how I entered the product and I seem to have complied with the proper setup for weight and volume. The shipping weight is 2 lbs and the dimensions are 6" x 6" x 6". I have the units set to lbs for the weight and in/ft for the dimensions. I have tried changing the package size to 1'x 1'x 1' but the problem remained.
Any hints
Charles

Nicholas,
Before you go spinning your wheels too much the very first shipping error has just resurfaced "Error while sending XML to UPS". I am positive that it is my setup because depending on which product I select for cart I may get one or the other error message. I will review every one of the 1100 products and see what 'I did' or 'am doing' incorrectly
Charles