Hi
I keep finding these little holes randomly in cotton t shirts and tops too. My machine is a Zanussi with a 7kg drum and 1200 spin speed.
I wonder if it is worth contacting the manufacturer (I've had it almost a year) as stumbling on this website has made me realise it may be the machine making the holes and not something in certain washes. It has ruined some first time washed t shirts in the process which is very annoying.