[Phanx]

Oh, I think I see what the problem is. Try this:

local debuffs = {}

local function UpdateDebuff(self, event, unit)
	if self.unit ~= unit then return end
	local DebuffBars = self.DebuffBars

	local numDebuffs = 0

	for i = 1, 40 do
		local name, rank, icon, count, debuffType, duration, expirationTime, unitCaster, isStealable, shouldConsolidate, spellID = UnitDebuff(unit, i)
		if not name then break end

		if DebuffBars.filter(self, unit, name, rank, icon, count, debuffType, duration, expirationTime, unitCaster, isStealable, shouldConsolidate, spellID) then
			numDebuffs = numDebuffs + 1

			local t = debuffs[numDebuffs]
			if not t then
				t = table_create()
				debuffs[numDebuffs] = t
			end

			t.name = name
			t.rank = rank
			t.icon = icon
			t.count = count
			t.debuffType = debuffType
			t.duration = duration
			t.expirationTime = expirationTime
			t.unitCaster = unitCaster
			t.isStealable = isStealable
			t.noTime = duration == 0 and expirationTime == 0
			t.filter = DebuffBars.enemyAuraType
			t.shouldConsolidate = shouldConsolidate
			t.spellID = spellID
		end
	end

	for i = #debuffs, numDebuffs + 1, -1 do
		debuffs[i] = table_delete(debuffs[i])
	end

	table.sort(debuffs, DebuffBars.sort or default_sort)

	local bars = DebuffBars.bars
	for i = 1, numDebuffs do
		if DebuffBars:GetWidth() == 0 then
			break
		end

		local bar = bars[i]
		if not bar then
			bar = CreateAuraBar(self, i == 1 and DebuffBars or bars[i - 1])
			bars[i] = bar
		end
		bar:Show()

		local statusbar = bar.statusBar

		local debuff = debuffs[i]
		bar.aura = debuff

		if debuff.noTime then -- something weird here
			statusbar:SetMinMaxValues(0, 1)
			statusbar:SetValue(1)
		else
			if DebuffBars.scaleTime then
				local maxvalue = math.min(DebuffBars.scaleTime, debuff.duration)
				statusbar:SetMinMaxValues(0, maxvalue)
				statusbar:SetWidth((maxvalue/DebuffBars.scaleTime)*((DebuffBars.auraBarWidth or DebuffBars:GetWidth())-(statusbar:GetHeight()+(DebuffBars.gap or 0))))-- icon size + gap
			else
				statusbar:SetMinMaxValues(0, debuff.duration)
			end
			statusbar:SetValue(debuff.expirationTime - GetTime())
		end

		statusbar.icon:SetTexture(debuff.icon)
		statusbar.spellname:SetText(debuff.count > 1 and format("%s [%d]", debuff.name, debuff.count) or debuff.name)
		statusbar.spelltime:SetText(not debuff.noTime and FormatTime(debuff.expirationTime - GetTime()))

		local r, g, b
		local color = DebuffBars.debuffColor
		if color then
			r, g, b = color[1], color[2], color[3] -- don't use unpack; 3 table lookups is faster than 1 function call
		else
			color = DebuffTypeColor[debuff.debuffType or "none"]
			r, g, b = color.r, color.g, color.b
		end
		statusbar:SetStatusBarColor(r, g, b)
	end

	for i = numDebuffs + 1, #bars do
		local bar = bars[i]
		bar.aura = table_delete(bar.aura)
		bar:Hide()
	end
end

Also, add this anywhere before the UpdateBuff and UpdateDebuff functions:

local table_create, table_delete
do
	local pool = { }

	local function table_create()
		local t = next(pool)
		if t then
			pool[t] = nil
		end
		return t or {}
	end

	local function table_delete(t)
		if type(t) == "table" then
			for k, v in pairs(t) do
				t[k] = nil
			end
			t[true] = true
			t[true] = nil
			pool[t] = true
		end
		return nil
	end
end

local default_sort = function(a, b)
	if a.noTime then
		if b.noTime then
			-- both timeless, sort by name REVERSE
			return a.name < b.name
		else
			-- a timeless, b not
			return true
		end
	else
		if b.noTime then
			-- b timeless, a not
			return false
		else
			-- neither timeless, sort by expiry time
			return a.expires > b.expires
		end
	end
end