I have found if a dispute is opened with paypal or I open an unpaid item disputes that sales will drop. I usually give buyers a fair amount of time to pay or if they want to cancel I accept, not anymore though.

Since last week sales have been down. Baybe it is just a fluctuation in sales, or ebays site is glitchy (is it not ever), or because I opened 3 non paying item disputes at the end of a good week. The day after I opened the disputes sales dropped.

Usually when ebay do their thing on the 20th sales seem to drop also.