I live in central CA. and this just started happening to me also . I thought it was our new high efficiency washer . About every 3 - 4 washes I started putting a little bleach in the whites and color safe bleach in the colors . And havent had a problem since . PS. I only use about 1/4 cup

I have had this happen in the summer time--especially with wet towels.

The bleach suggested by LeeA. works and vinegar will work also. The biggest key is to get them into the dryer quicker!

I also leave the lid open on my washer between loads so that it dries out and doesn't stink.

I had this problem on a grand scale last summer when my part of Topeka was hit bu flash floods.

Fema came and saved the day, but meanwhile I had tons of mildewed stuffed animals, clothing, blankets and clothing to attempt to save.

Hot water wash everything with bleach is the only known cure for the dreaded mildew and sometimes that isn't enough. I'm sure it will be fine for your problem though as with me it was mostly thick bedspreads, pillows and stuffed animals that didn't survive

Oh i should have mentioned that if its a problem with the washer you might also try a little CLR in a hot water wash with bleach. With No clothing of course

Amen to this comment I had forgotten about the tip of leaving the lid up slightly or the door open slightly to really air out the washer . My washer also came with clean washer method to do every so often, this might also help. Run with liquid bleach and no clothes, please ck. owners manual to see if they have cleaning tips.