Bitcoin-Qt is now running nicely using around 0.9% CPU. So it seems like
> the culprit was indeed line 31:
>
> if(mq->timed_receive(&strBuf, sizeof(strBuf), nSize, nPriority, d))
>
> Others, who have seen similar issues ?
>
>
I can definitely reproduce the issue on my mac.

If I recall correctly, the Mac Bitcoin-Qt does not register itself as a
bitcoin: URL handler, so the easiest fix for the 0.6 release would be to
just never launch the ipcThread #ifdef Q_WS_MAC


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Gavin Andresen