Does using custom data attributes produce browser compatibility issues?

I would advise in favor of data attributes for the following reasons:

• ids need to be unique document-wide. Thus they are limited in the semantics they can carry
• you can have multiple data-attributes per element

and probably less relevant in your case:

• changing ids might break idrefs

However, I'm not sure whether I understand your specs completely as extracting the element id in jQuery is as trivial as getting the data attribute: $('.foo').attr('id');.

You might be interested in Caniuse.com, a browser compatibility site for web technologies.

If XHTML is an issue to you, you might also be interested in how to use custom data attributes in XHTML: see here for a discussion on SO and here for an XHTML-compatible approach using namespaces.

this guy says data attibutes work on IE6.