In the three Years I have been using Ebay I buy from a lot of the same Sellers and communication regarding our various transactions are usually very good.
When I have won,or bought an item I always email the Seller telling them that I have just paid via Paypal,or just sent a Cheque,or Postal order and look forward to receiving the item.If it is a Postal Order,or cheque I ask them to confirm receipt of my payment when it arrives.
Some Sellers hit the "Payment received" key when payment is received which is fine,but in some cases despite follow up emails requesting confirmation of receipt of payment,or when the item will be posted these are quite often ignored.
In some cases the only comunication you have from a Seller is when your item turns up through your letter box,usually late,or only because you have relentlessly hassled them with emails,or threatened to open a Dispute so they just want to get rid of you.This is sad and is not the norm,but is fairly widespread.
Finally, I really think that where Sellers accept Postal Orders,Cheques or other means of payment than Paypal you do not see"Sellers details not on File with Ebay"when paying for an item.You then,in many cases send 2/3,maybe more emails trying to obtain this info,and when you get it you get no explanation why it has taken so long to send it.
At the moment i just hit the communication bit in feedback and give the lowest score possible,but this doesn;t alter the fact that I have spent a considerable amount of wasted time emailing for something that should be available anyway.
I know i sound like a "Grumpy old man" but anybody who deals with me knows I am not,and I must stress these instances are not the norm,but appear to be on the increase.