I always clarify what each shipping option includes, tracking or not, shipping time, cost, etc... in the item description, as well as an automated screen/message generated by ebay ... + I send them a manual email/message every time I get an order... tell them clearly all the above details. Then if they want to cancel the order or add tracking / upgrade shipping etc.. they have 12 hours to do so.. if I dont hear from them, I ship the order within 1-2 handling days. Still going strong on 100% pos feedback in abt 2 years of operation and a total of about 1500feedback over 3 accounts.

So I recommend doing the same.. particularly with the current shipping option changes/problems that are occurring.

& if they do end up being upset, just offer a discount on next purchase... or upgrade them to include tracking for free or something.. take it on the chin. Most people are pretty understanding though in my experience.