My self as a Front End Developer, for many years I have resolved many browser and CSS related issues for Developers coding in ASP, PHP and XSLT.
I just want some Front End Designers and Developers to point out, which things to be consider when there is some Design issue in Programming.
Firebug is one option.
Designers and developers often have a symbiotic relationship. In my opinion, all developers should have (at least) very basic design skills and all designers should know a thing or two about code. I don't mean that the two professions should be able to do the other's job; just that each should have a general idea of how the other goes about solving problems. Much of the animosity frequently seen between form and function comes from either side not understanding the other.
On a more specific level, a developer can benefit from knowing HTML and CSS in that they can see what the designer is doing and make revisions if necessary. Better communication will result in better products, and the two professions can't communicate without knowing the same languages.
Where I worked, 'Design' is anything image-related, and 'Development' is anything code related. Designers work in Photoshop and sometimes an HTML editor, and Developers work from an IDE.
The designer can do HTML and CSS, but the developers often need to tweak it to work with ASP.NET (change input controls server controls as needed). The developers could probably resize or recolor an image if need be, but are not as fast as the designer. Designers usually do their work upfront and the developers do the ongoing work.
By your definition, I am between a front end developer and back-end. The separation of concerns is not always clear.
Evan Meagher is right when to say, "Much of the animosity frequently seen between form and function comes from either side not understanding the other." It is the same for any two departments that need to work together. A way that you can smooth over the animosity, helping your teams understand each other is to have them talk to each other before any fights start. Maybe you could have a lunch and learn, where front end developers describe what they do, and some nuance of a particular project, and invite your backend developers to do the same next week.