I have a theory about that and, while I wouldn't want to steer you wrong, I'll pass it along. People expect to be warmly greeted the first time they come to a new church and, if they are, they are disappointed if that seems to cool in the weeks that follow. But there is another side to that coin that isn't as well appreciated.
For the first time or two you show up, many members feel that it's their duty to speak to a newcomer and make him feel like coming back. However, they also realize that a lot of visitors will NOT continue to appear at their door for the simple reason that they're checking out a number of churches. As a result, the really genuine feeling of being among friends doesn't develop until you've attended fairly regularly for some weeks and the people there recognize your face and assume that you are for real.
Of course, it REALLY helps if the visitor does his part, too, and remembers names, says 'hello' to the regulars during return visits rather than expecting everyone else to take the first step, and perhaps also says something to them about something that was learned during the initial visit.
This is not your first visit to this church, but because you've come and gone, you may be assumed to be only making one of your occasional stops. I'll bet that if you keep going and take the lead to show this time is different, perhaps by also coming to some event other than the Sunday morning worship, you'll see a change. I could be wrong, of course; some churches are just not friendly. But I wouldn't write these people off yet, especially because you like other things about the church.