I got my Droid 8/31/11. My WIFI stopped working last week and couldn't be fixed so I had to get a refurb from Verizon. I hope this is not a trend.
Its technology, problems happen. Wifi issues could be caused depending on what type of encryption is used, channels, etc.
A word of advice.
Put the replacement through the wringer. I did that with the replacement D3 I received and so far so good.
Sent from my XT862, while on the move.