Well, this is sorta the SCJA forum, but here we go:
What you should do is take the SCJA exam. It is on Java 1.5, but doesn't go too in depth on Java 1.5 constructs. You don't need to know RegEx or anything like that, just basic syntax for Generics and a for:each loop.
So, get you SCJA certification on Java 1.5, and you can say that you are Java 5 certified on your resume.
Then, take SCJP 1.4, which is said to be a bit easier than the SCJP 1.5 exam. So, then you can advertise both being a Sun Certified Java Programmer, and a Sun Certified Java Associate, on Java versions 1.4 and Java 5.