Anyone getting failed log-ins from own IP address whilst logged in?

I'm logged in, and have been for hours (using basic Betfair interface, and Gruss) but got stopped from placing bet because account was locked due to failed log-ins. Account security screen shows that these attempts were from my own IP address. (I'm the only one in the house).

This is the 2nd time it's happened in the last 2 weeks.

Anyone else had this?