Maven clean + build causes project in Eclipse to show errors until clean in Eclipse

We have had the exact same problem a while ago. We had more than 20 projects giving the same kind of error. From the investigation we did, we concluded that when maven clean install is run, eclipse loses track of the class files and thinks some of them are undefined. The solution we had is to issue the following at the command line:

mvn eclipse:clean
mvn clean install
mvn eclipse:eclipse