USPS oversized items shipping cost

See http://pe.usps.gov/text/qsg300/Q120.htm
It explains how the 32*8*8 inches will automatically charged at a dimensional weight of 11 pounds, even it it only actually weights 3 pounds.    Product card allows to put the size into the products backend, but ignores the dimensional weight rule for USPS. 
Katharina

Hi Katharina,
     Is the product definately marked as "oversized" via the radio button - I guess so as your post subject uses that word, but it's worth checking.
I just started a quick look at ShipRates.asp and the calculation is currently done as follows :-

USPS_PackageSize=(Cint(session("USPSPackLength"&q)) + ((Cint(session("USPSPackWidth"&q))*2)+(Cint(session("USPSPackHeight"&q))*2)))

-- Basically summing length & girth. Which for your parcel works out as 32+16+16 = 64 Which maps to Regular in the code.
REGULAR < 85  (See (1) below)
For totals over 131, USPS is, I believe, disabled.
 
Looking at the USPS website the CRUCIAL point seems to be the ZONE that the package is being shipped to as different rules apply :
<snip>
1)  Parcels addressed for delivery to zones 1-4 (including local) that weigh less than 20 pounds but measure more than 84 inches in combined length and girth (but not more than 108 inches) are charged the applicable price for a 20-pound parcel (balloon price).

2) Parcels addressed for delivery to zones 5-8 that exceed 1 cubic foot (1,728 cubic inches) are charged based on the actual weight or the dimensional weight (as calculated in 123.1.3), whichever is greater.
</snip>

It seems the current calculation is handing the Zone 1-4 but not the zones 5-8
I must say the USPS system seems very complex.
As I don't have any info about USPS postal zones this is where I come unstuck, but I guess they are basically dependent on the distance from the shipping point, so a table of ZIP codes would probably be useful in discovering the "zone". It may well be already in PC - but as I don't use it I'm not familiar with it.
 

Hi Katharina,
    This one woke me up again - why do some problems just stick in my head?
Anyway,
Your package at 32 * 8 * 8 equates to a "REGULAR" package (32+16+16)=64 which is <85.

According to the USPS API it will ignore the Length / Width /Height for "REGULAR" (I'm assuming  this is a domestic shipment). 

http://www.usps.com/webtools/htm/Rate-Calculators-v1-2.htm - see 2.1.3

This doesn't square (at least in my head) with it using dimensional weight. There's no mention on the USPS  of dimensional weight at all. I'd check with USPS why this is as they seem to be missing something here.

There is code in ShipRates.asp that passes the dimensions in certain circumstances to USPS, so it's a fairly trivial change to add them for a "REGULAR" "priority" package, but according to the USPS doc it will be ignored. It may be worth experimenting by adding it and running a test order though.

Have you raised a support ticket with EA for this?

I've just raised a ticket with EI.  Your input was really helpful, because now we have narrowed down what seems to be causing it.  You are a charm and always so helpful.
Thanks,
Katharina