Is it my washing machine staining my clothes?

I live in an apartment, so i do not know the history of the washing machine, however it seems like 1 out of e 5 washes, several articles of clothing are damaged.i have since become dilegent about washing white & colours seprataly, but my latest disco was that after doing a cycle of whites, i washed my green duvet cover by itself, it came out stained!! i washed it on a medium temperature.the stains are always of the same consistancy - a dark, patchy, partly translucent stain. could it be from using a detergent that is dark colored?? or i wondered if the water coming into the washing machine could be pre-strained from another apartments washer??thanks in advance!
Answer
The stain is from your fabric softener. you may be using much, or you may not be diluting it with water. there is a chance that it could be your detergent...but probably your fabric softener. if it is your detergent...it would be from pouring your liquid detergent directly onto your clothes. i always dilute it with water before pouring it into the machine.