I think its just a roku quirk as a reboot see's it work fine only after a few apps have been used & closed does it prevent it working.
Having said that i cant play it over smb only over nfs.
Roku HD1500 rev b
Sony Bravia LCD
Yamaha AV gear
Sky HD........January !! if they release it as promised! - they didnt, now they want Â£300 !!!
Roku, maybe its time for the mini mac core duo ???