Reporting Services Login prompt when deploying solution - SSRS

Just spent 20 minutes fathoming out this issue. I've been transferring a SSRS solution between a 'test' laptop and my work PC, both using local reporting services servers. Whilst deploying an rdl I got a Reporting Services Login prompt, having never seenone before in BIDS I had to do some google searching. Inially I thought it was something to do with IIS security settings but eventually realised that TargetServerURL value was pointing to my other server. So it was simply a case of adjusting this value. Suprised I haven't witnessed this before as I'm sure I've made this mistake in the past