countryblue1027, as usual eBay's employees have no clue as to what they are talking about.
What I have been doing before this Auctiva error message today is listing Fixed price listings using the 10 day via Auctiva, then revising the listing on eBay and it allows me to change it to the 30 day and does charge the 35 cents listing fee.
Thus, it is already in effect, just not done here at Auctiva yet.