No 5.1 in SD on Channel 12 (WISN)

[sp44again]

I thought when I had TWC that any show that wasn't in HD was still 5.1 in SD and it worked. When I turn to 12-1 the receiver switches to 5.1 but I get no sound. Any ideas to why? It works when a HD show is on though. :confused:

P.S. I don't have TWC anymore I'm using a OTA box now.

[sp44again]

Noboby?