Sadly, I can't recall a Sunday in recent memory where there hasn't been a problem on Auctiva big enough to block me from listing anything.
Sunday is a bad, bad, bad day to list through Auctiva, because the smart sellers know that stuff goes for more money if it ends on Thursdays or Sundays, so you have both the 7-day Sunday enders colliding with the 5-day thursday enders for one hell of a bottleneck trafficjam on Auctiva's desperately-in-need-of-revamping servers.
I've started listing on Thursdays for 7-day, so it starts on a quiet(er?) day on Auctiva and ends on a busy day for eBay, but quiet day for Auctiva. I know that if things get really insane, I can switch the Auctiva lister over to html, cut and paste the html right into eBay, and pop on photobucket to upload my pics instead of being forced out by Auctiva's lack of ability to handle images at the moment. More steps? Sure it is. But if you really care about your work, you "work" for it!
Auctiva higher-ups - I hope you're catching on to the recurring theme here amongst your serious sellers and dedicated users. We like free, but we are willing to pay for a modestly-priced subscription upgrade *alternative* to run alongside your free service, in order to free ourselves of these (at this point) permanently recurring critical issues on the largest listing day.
Thanks;
-Fox