Developers think of design as Black Magic*. Really.
For the most part developers just don't understand how you (the designer) can take a few images toss them into Photoshop and come up with a series of slick new designs without the help of some kind of dark spirit. They might be familiar with the software, they might even watch you work over your shoulder, but ask most developers to come up with a logo and you might as well be asking them to conjure a poodle out of thin air.
So what does that mean? It means that most developers view design with a certain amount of reverence - and fear. It can do great things and help Vice Presidents appreciate their hours of toiling behind the scenes to make things go. And it can strange and terrible things, like make them work nights and weekends (again so those same VPs will be duly impressed).
This combination of awe and fear that most developers have with the field of design, can make them act downright hostile toward designers. Usually this is the result of being burned in the past, but it is something that can be overcome.
Reaching out to developers and letting them know you are on the same team and that you've got their back, can go a long way to alleviate fears. If you actually deliver on watching out for them, even better. Everyone feels better going into battle with a shaman on their side. And who knows? They may eventually come to see your voodoo as something they just can't live without.
* Just to clarify things, in this particular case "developers" means your typical back-end developer with a Computer Science degree, not your friend Joe, who used to be a designer, but now spends more time writing HTML5 & JQuery.