Strange Emule Error Message

[Darth Sushi]

[9:56:49] peqssu:[AUTOMATED ERROR] Your client is probably using stolen client hashes has been banned

[Arathorn]

Do you have "use secure identification" switched on (security tab).
On older clients it could be possible that a leecher mod stole your user hash to use your credit.
Anyway if you don't get it often you don't have to worry. Otherwise do a clean install of eMule.