Registration Requirement for Oral Cop On Minor Violates Equal Protection Clause. (Or, What a Difference a Judge Makes)
Case: People v. Hofsheier, no. H026217 (Cal.Ct.App. (6th Dist.), Apr. 1, 2004)
Proceeding: Direct criminal appeal following guilty plea.

Holding: Imposing a sex offender registration requirement for consensual oral copulation with a minor but not for sexual intercourse with a minor violates equal protection.  (This case involved a 22-year-old defendant and 16-year-old minor.)

In so ruling, the Sixth District disagreed with its own opinion in People v. Jones (2002) 101 Cal.App.4th 220. What changed? The judicial lineup. In Jones,  Justice Patricia Bamattre-Manoukian wrote the majority opinion, joined by (Now Presiding) Justice Conrad Rushing.  Justice Nathan D. Mihara dissented in Jones. In the current case (Horsheier), Mihara authored the majority opinion (joined by Justice William M. Wunderlich) and Justice Bamattre-Manoukian dissented.

In addition to changing lineups on these cases, there's another reason this issue won't go away. The majority's willingness to find that no rational basis for the disparate treatment for oral copulation and intercourse was based on the fact that the prosecutor and the trial court agreed the distinction was irrational:

Because defendant’s assertion that there was no rational basis for the distinction was conceded below, and no evidence to the contrary has been produced, we must conclude in this case that the legislative classification lacked a rational basis.

Writing for the majority, Justice Mihara noted that "this issue has now reached this court three times, but no one has yet produced any statistics regarding the relative rates of recidivism. We publish this case to encourage the final resolution of this issue in some future case by the production of such statistical evidence in the trial court." Theoretically, differing rates of recidivisim for the two classes offenders could justify the distinction. (It's also possible that Penal Code section 290 has been amended so many times and is so long and so complicated that it's simply just a mess.)