okey - that is *weird* since if there are no references where is it coming from ;(
did you search .settings folder too ?
Before we push this to a bug report please check the following:
1) Is there an actual /dev folder in your source folders ? (i.e. MyProject/WebContent/WEB-INF/dev) ?
There could be from "old" times - remove it please.
2) Is there an actual /dev folder in your build folders ? (i.e. MyProject/build/dev) ?
there shouldn't be - just checking.
3) Is there an actual /dev folder in your deploy projects ? (i.e. MyAppServer/server/default/deploy/MyProject.war/WEB-INF/dev) ?
If there is - remove it, heck, remove the whole MyProject.war folder/jar to be sure we got all cleaned out.
4) Rebuild
If none of the above works then please try and reduce this to a minimal project and attach it to a new jira since something is weird here then!