Problem with Looting and Questing

Me and my friend started your server today, but he have a strange problem with delay, when he tries to loot a mob it simply dont open, and when he tries to take quest...dont open either, he have to click it lots of times to open quest...i searched in google but dont find any info, we played other servers before and there was no problem....he has above 100fps and around 40-50ms ping....everything else is OK...but that, what can that be from, please answer...any info can help...
P.S. he is playing from Laptop if that matters....