I've found that the soft spouted Avent cups are hard for him to drink out of - although he may just not "get it" yet. Actually, I tried drinking out of it, just to see why he wasn't getting anything out of it, and I thought you had to suck pretty hard! We'll give it another go, just to keep trying!
I've actually gone in to the daycare when he should be ready to eat (I only work about 5 minutes away) to try and trouble shoot. The only major difference between what they are doing and what I do at home is the fact that there are lots of distractions! On one of the days, he wouldn't even eat for me. Now, granted, we think he was teething and was overall kind of cranky, but he wouldn't even take a drop from me! We use bottled water at home, and I even send the same water we use at home in his bottle to daycare every day.