If the stem looks like it's watersoaked, it may be Damping Off, caused by a fungus.

Maybe a bit less water and more air circulation would help.

Once the plant is affected, I don't think they get better, but others here may know better.

Sue

Is it dying at the stem level, or just sprawling? My squash grew, flopped, and just started to crawl in whatever direction seemed to offer the least amount of resistance. So... yeah a picture would definitely help :3

To post pictures your best bet would be to open a Photobucket account (http://www.photobucket.com), upload your photos, and use the handy links they provide for you (you will want to use the one labeled "HTML tag" or something of the like).

Hopefully this picture posts, melonpocky, thanks for the info on posting pictures. You will see the one on the right looks good, the one in the middle is tipping and the one on the left is just coming out.

{{gwi:41215}}

Here is a link that might be useful: backyard farming

It looks perfectly healthy so I think it will right itself. I don't think it is tipping over. Rather it has just not uncurved yet after germination. You need to rotate the pots gradually each day so they get equal amounts of light all round. Also I'd have them standing in a tray of some sort so that they don't leak on your sill and/or dry out. In fact I'd probably cut off the net stuff and put them into yoghurt pots or similar to keep them at a more constant level of moisture and warmth and to prevent the roots getting restricted when potting on or planting out. There is not enough compost in those netty things to keep them going for long.