I wash all my nappies together sometimes at 40 sometimes at 60 and it doesn't seem to affect the fuzzies. However I've only been using cloth forth a couple of months so I don't know if there would be long term damage.
Annette, I've been using my med Fuzzis for a year just about now and i always wash at 60 or 50 and I've never had a problem, they all look really good still (except one that I bought 2nd hand which now that I've seen how mine look must have been used on at least 2 kids before!!! not such a bargain!!). They are normal PUL so I can't understand why they put that on the label!
I just wash mine with all the others and havent noticed any difference. I think from when the FB lady came out she said something about the high temps do affect the nappy after a while but I think thats if you were to do a hot hot wash everytime.
Ruby cluster feeds from when Isaac goes to bed at 8 til about midnight, so I just stay up til her 3am feed, and get everything done (washing, tidying, cleaning, paying bills, ironing etc), otherwise it just doesn't happen.