I am getting the following using shipping from South Carolina to Minnesota 53575 ...

1 of .2
United States Postal Service (1 x 0.20lbs) (Express Mail (1 - 2 days)) $19.80
United States Postal Service (1 x 0.20lbs) (First-Class Mail (2 - 5 days)) $1.51
United States Postal Service (1 x 0.20lbs) (Priority Mail (2 - 3 days)) $4.95
United States Postal Service (1 x 0.20lbs) (Parcel Post (4 - 7 days)) $8.25
United States Postal Service (1 x 0.20lbs) (Media Mail) $2.23
United States Postal Service (1 x 0.20lbs) (Bound Printed Material) $2.34
United States Postal Service (1 x 0.20lbs) (Library) $2.12

2 of .2
United States Postal Service (1 x 0.40lbs) (Express Mail (1 - 2 days)) $19.80
United States Postal Service (1 x 0.40lbs) (First-Class Mail (2 - 5 days)) $2.02
United States Postal Service (1 x 0.40lbs) (Priority Mail (2 - 3 days)) $4.95
United States Postal Service (1 x 0.40lbs) (Parcel Post (4 - 7 days)) $8.25
United States Postal Service (1 x 0.40lbs) (Media Mail) $2.23
United States Postal Service (1 x 0.40lbs) (Bound Printed Material) $2.34
United States Postal Service (1 x 0.40lbs) (Library) $2.12


Make sure you have the current version of USPS, following the instructions to Save settings, REMOVE, INSTALL and re-configure:
http://www.zen-cart.com/forum/showthread.php?t=97461

Check your Machinable setting as well ...