Ist signin.ebay.co.uk sicher?

Have used eBay to buy and sell goods, have had some problems like selling an item and not getting paid via PayPal but eBay sorts it out, have also brought items from Hong Kong and had no problems. Had ONE major problem, sold a computer on eBay brand new, buyer then opens a case saying its faulty, I execpted the item back from new to dusty, scratched and dirty so I opened a case on the buyer...eBay then took his side and refunded him but I escilated the case further and they did not take the money off me. eBay is more on the buyers side but do in some cases help out the sellers as well. All I can say is be careful selling and buying, also be specific about refunds and returns.