Spider plant question.

Spider plant question.

My spider plant has been doing better than any other plant I have, I think. But in the past week or so, I noticed that it was getting a lot more dry, brown leaf tips (I know that this is usually from using tap water - I use filtered water that has been sitting in the watering can until it is room temperature), and also that several leaves had gotten yellow and dead looking. When I pulled these leaves off, I noticed that the base of the leaves were dark and soft. I'm wondering if it sounds like I'm overwatering even though I only water when the soil seems dry? I do water the plant at least once a week, and sometimes it feels kind of dry more often. I mist it lightly, occasionally. Not sure if I'm imagining it or not, but the babies seemed to have lightened in color, and maybe become a little less green, a little more yellow. It's not directly in front of window, but across from one by about ten feet. It gets a good amount of less than totally direct sunlight just about every afternoon. Any thoughts? It's a beautiful plant, I don't want to lose it.
6/19/07 Pix of our garden

6/19/07 Pix of our garden

My couch

My couch

the only blemish

the only blemish

Early Morning Treasures

Early Morning Treasures

Ant invasion in winter??

Ant invasion in winter??

Plant ID and care tips

Plant ID and care tips