iChat with Yahoo Messenger keeps prompting about the same buddy requests
Sadly, the problem lays in the chat protocol between the Mac and Yahoo.

The only solution I've found is to log on with a Window's machine using the latest Y!M client and doing the decline/ignore there.

I was up to 15 messages requests between my two acts every time I woke my Mac from sleep. Going to the Yahoo client on Windows cleared this up entirely.