[Derision]

I've just had a look at the client disassembly and it is comparing lu->level with lu->level_old and adding 5 skill points if lu->level > lu_level_old, so in fact lu->level_old should be set to the max level the player has previously reached (m_pp.level2). This seems to work:

void Client::SetLevel(int8 set_level, bool command)
{
        #ifdef GUILDWARS
                if(set_level > SETLEVEL) {
                        Message(0,"You cannot exceed level %i on a GuildWars Server.",SETLEVEL);
                        return;
                }
        #endif

        if (GetEXPForLevel(set_level) == 0xFFFFFFFF) {
                LogFile->write(EQEMuLog::Error,"Client::SetLevel() GetEXPForLevel(%i) = 0xFFFFFFFF", set_level);
                return;
        }

        EQApplicationPacket* outapp = new EQApplicationPacket(OP_LevelUpdate, sizeof(LevelUpdate_Struct));
        LevelUpdate_Struct* lu = (LevelUpdate_Struct*)outapp->pBuffer;
        lu->level = set_level;
        if(m_pp.level2 != 0)
                lu->level_old = m_pp.level2;
        else
                lu->level_old = level;

        level = set_level;

        if(IsRaidGrouped())
        {
                Raid *r = this->GetRaid();
                if(r){
                        r->UpdateLevel(GetName(), set_level);
                }
        }
        if(set_level > m_pp.level2)
        {
                if(m_pp.level2 == 0)
                        m_pp.points += 5;
                else
                        m_pp.points += (5 * (set_level - m_pp.level2));

                m_pp.level2 = set_level;
        }
        if(set_level > m_pp.level) { // Yes I am aware that you could delevel yourself and relevel this is just to test!

#ifdef EMBPERL
                ((PerlembParser*)parse)->Event(EVENT_LEVEL_UP, 0, "", (NPC*)NULL, this);
#endif
        }

        m_pp.level = set_level;
        if (command){
                m_pp.exp = GetEXPForLevel(set_level);
                Message(15, "Welcome to level %i!", set_level);
                lu->exp = 0;
        }
        else {
                float tmpxp = (float) ( (float) m_pp.exp - GetEXPForLevel( GetLevel() )) /
                                                ( (float) GetEXPForLevel(GetLevel()+1) - GetEXPForLevel(GetLevel()));
                lu->exp =  (int32)(330.0f * tmpxp);
    }
        QueuePacket(outapp);
        safe_delete(outapp);
        this->SendAppearancePacket(AT_WhoLevel, set_level); // who level change

    LogFile->write(EQEMuLog::Normal,"Setting Level for %s to %i", GetName(), set_level);

        CalcBonuses();
        if(!RuleB(Character, HealOnLevel))
        {
                int mhp = CalcMaxHP();
                if(GetHP() > mhp)
                        SetHP(mhp);
        }
        else
        {
                SetHP(CalcMaxHP());             // Why not, lets give them a free heal
        }

        SendHPUpdate();
        SetMana(CalcMaxMana());
        UpdateWho();
        Save();
}