[fletch]

It would help if you posted an example so we cauld see what the problem is. Without that we can tell you what the options are:

1. Motion blur or camera shake: You shutter speed is to slow and the blur is being caused by you moving the camera or people in shot moving during the exposure. This will give you streaky pics with poorly defined edges.

2. Out of focus - Using a very large aperture will mean your focus has to be spot on to the inch. This can be difficult in low light. If it isn't you will get blury soft pictures.

3. ISO noise - If you are using very high ISOs you could get a lot of grain and maybe some softening due to over agressive noise reduction. This will give you either a speckled look or have all of the detail look smeary.

Without the pics I couldn't tell you what is wrong. You shouldn't need high speed sync when taking pics indoors though. That is for shots in bright light where you need the flash as fill but the ambient light is too bright for the flash sync speed.