We had been using nothing higher than JDK 6 with our project up until now, but when I built a new build machine using Fedora 18, JDK 7 was our only real option (okay, that and JDK 5). However, once I got things building using ant, I got the following cryptic error in the unit tests:

java.lang.VerifyError: Expecting a stackmap frame at branch target 41 in method com.m2mci.correlation.CorrelationId.equals(Ljava/lang/Object;)Z at offset 24

After some digging, I found out that the kind folks at Oracle/Sun had changed the bytecode in JDK