Thank you very much for the detailed info on this. I have been doing some testing to see what is going on and confirm your results so that I can get proper bugs logged for these issues. I'm having a problem with the USPS shipping server issue. When I run the checkout wizard the code that it outputs has this service or carrier code present and set to the value that I selected in the wizard. I tested this out with eCart 4.5.2 in CS4. I just ran the checkout wizard and selected Payflow link as the checkout type then filled in the values that I was prompted for along the way. I noticed on the page where I was selecting the value for this service type I have to select the lightning bolt icon next to it after the fact or my changes did not seem to be taking. If you can please perform one more test on this and try setting the focus to another control on that step of the wizard after you set the type. Let us know if the issue persists for you like this and I can get a ticket opened so we can investigate further.