Error: please choose a carrier with 1 page order and NO carriers

[damnated]

I have 1 page order setup with no carriers (only downloadable stuff on the site), and the following thing happens: if I add a product to the cart from the product's page and check out I get the following messages:

Choose your delivery method

There are no carriers available that deliver to this address.

Choose your payment method

Error: please choose a carrier

This is presumably a bug, because if I click on the "add to cart" from the home page for instance, and check out then, everything works just fine, and I get the following messages:

Choose your delivery method

No carrier needed for this order

Choose your payment method

Paypal logo appears, it's clickable and directs me to pay pal where I can log in etc. In other words, this way everything works just fine.
How can I get around this? Please advise!

[sunandmoon21]

I also get "Error: please choose a carrier" message at checkout, even that I have the carrier set up properly (also adjusted to the actual zone). I use PS 1.4.1

Anyone can help?