Replication of an issue with enum quality after summer12 salesforce upgrade.

LolEnums.cls

global class LolEnums implements Database.batchable<sObject>, Database.Stateful{
    public enum Places {FIRST, SECOND, THIRD}
    public Places val;
    
    global Database.QueryLocator start(Database.BatchableContext bc) {
        val = Places.FIRST;
        return Database.getQueryLocator('SELECT id FROM User');
    }
    global void execute(Database.BatchableContext BC, List<sObject> work){
        System.assertEquals(val,Places.FIRST);
    }
    global void finish(Database.BatchableContext BC){
    
    }
}