Welcome to JavaRanch.
Have a look at
Sun's SCJP page and the
SCJP FAQ.
You can do CX-310-055 (SCJP 5) or CX-310-065 (SCJP 6) instead of SCJP 1.4. These exams are about Java 5 and Java 6. There is no SCJP exam for Java 1.4 anymore; Java 1.4 is obsolete.
There are upgrade exams (CX-310-056 and CX-310-066), but these are only for people who already have an older SCJP certificate and who want to upgrade to a newer SCJP version.
CX-310-036 is not the replacement for the SCJP 1.4 exam; it is the old SCJP 1.4 upgrade exam, meant for people who wanted to upgrade to SCJP 1.4. It is discontinued, just as the full SCJP 1.4 exam (CX-310-035).
[ November 18, 2008: Message edited by: Jesper Young ]