I haven't noticed any lag time in my listings, other than on the Active Listings page. I us the scheduling feature for my listings, and they go up right on time... You might need to submit a help ticket to the support staff, but I'd wait and see if anyone else responds to your post to see if it's a common problem for other folks.
I've been really impresses with Auctiva so far, and I hope your situation gets straightened out soon. Good luck!
2purrcats