Linux XBMC freezes if my NAS drive isn't on before XBMC boots up

Some time I forget to turn my freenas on before I start XBMC and when this happens I go to play a movie via xbmc constellation app (not sure if this problem still exists if I just navigate. I'll edit it if not) and it freezes xbmc (NAS is on, just booted up after xbmc did). My xbmc is set to scan for new file when it boots up which I have a feeling that it may be the cause of it freezing. (I'll try turning it off and checking). But I would like for it to run fine with the current setup. Any ideas, is this a common problem?

Thanks

You could use WOL and the Advanced Wake On LAN Add On?

ATM my NAS doesnt support wake on lan and also XBMC is freezing if it boots up after the NAS as stated which is why im wondering what the problem is