I've not found this issue on this forum, but my initial thought would be to have the wireless computer on in the same room, and then re-sync the sub. (Press reset in the back for 4 seconds, and hold down the mute button until the lights on the display stop).
Keep me posted.
Recently bought the above referenced sound bar which has a wireless sub woofer. System sounds great however it appears to be causing interference with other wireless devices. Specifically I loose my wireless signal on our laptop if in the same room as the sound bar. I have seen this as a complaint from some other customers on retail web sites however I have not seen any suggestions on how to rectify the problem. Do you have any suggestion?