Canada post Module won't allow large pieces

I just downloaded and re-loaded the lates update to Canada Post Shipping Module. I did this because My clients when purchasing a larger type item would get this message when checking out" Item is too large to be packed.
If you prefer to use Canada Post as your shipping method, please contact the The Trailing Edge via Email."

On the previous page the following options would be listed:

Estimate Shipping Costs
Ship to: XWZ
422rue de la T
Gatineau, QC J
Canada
Available Shipping Methods Rates
Store Pickup (Walk In) $0.00.
Now obviously I'm missing something. Smaller items have no problems. Also I can get a shipping price for the identical size of larger items as well as weight on Canada Post Site.
Can anyone tell me what I'm doing wrong or what configuration in the shipping module do I have to change.
Thanks for your help.

You need to login to your Canada Post SellOnline account and configure boxes to suit the dimensions of the products you've configured in your store.
The CP module tells the CP server what your product sizes are, and the CP server then tries to fit those products into the boxes you've configured in your CP account.
Your error message is confirming that you've not set up appropriate boxes in your CP account.