Mixing nimh batteries

I'm running a independant nimh battery charger and wanted to charge 4 rechargable nimh batteries ..

2 duraloops AA nimh 2000mah

1 energizer regular AA nimh 2300

1energizer regular AA nimh2100

the manual says don't mix batteries ...is that right or wrong...That's why i wanted to buy a independant charger ..so i could ..am I losin it ?

which has a similar warning...........I ignore it. Neither the batteries, charger or I am showing any ill effects....so far.

it's interesting how they came off the charger ( actually 8 hours later /just sitting in a shut down charger )

1 duraloop 1.435 < seems very high

2 duraloop 1.405 < what i would have expected

3energizer 2100 1.385 < expected /old batteries

4 energizer 2300 1.375 < more junk /old

The 1.435 volts after an 8 hour rest surprises me ..Maybe these batteries are just waking up after very long nap. they may only be on their second or third charge .

If the charger is really working the channels independently the warning makes absolutely no sense. What kind of charger is it?

1.4 - 1.45V is perfectly normal for a fully charged NiMH without load.

http://www.amazon.com/Sony-BCG34HLD2RN-Charger-Pre-Charged-Batteries/product-reviews/B003GS6FIE/ref=dp_top_cm_cr_acr_txt?ie=UTF8&showViewpoints=1

it is the 5$ amazon find that agenthex pointed out a few days ago .. it came 2 days after purchasing I also have a duracell cef23 on the way .thanks to some people on the forums .I wanted to be able to charge off of DC as well as AC.