It's not just people with zero feedback. In fact, the vast majority of non-payers for me are not newbies... come to think of it, I don't think I've ever had to file against someone with zero feedback.
That's just my experience, though. Have you contacted them to remind them that they need to pay? Could be they just forgot, or, owing to inexperience, don't know how to proceed with payment.
I'll typically send reminders at the 3 day mark and the 6 day mark. If I don't hear anything at all from the buyer, I'll file after 7 days. If the buyer requests a few more days to pay, I usually allow it.
If you've already sent reminder to them, and they haven't responded, then go ahead and file after 7 days. If you haven't tried to contact them, you might try sending a reminder, and give them an extra day or two.