Just installed 5.2.3, here's what I get when I attempt to open bags with nothing but Bagnon loaded. Going back to 5.2.1 corrects it.

Date: 2013-04-21 19:10:11
ID: 1
Error occured in: Global
Count: 1
Message: ..\AddOns\Bagnon\main.lua line 116:
attempt to index field '?' (a nil value)
Debug:
Bagnon\main.lua:116: CreateFrame()
Bagnon\main.lua:100:
Bagnon\main.lua:97
(tail call): ?
Bagnon\main.lua:201: ToggleAllBags()

Locals:
self =

{
SetDefaultModuleLibraries = defined @interface\AddOns\Bagnon\libs\AceAddon-3.0\AceAddon-3.0.lua:381
SearchFrame = {
}
EnableModule = defined @interface\AddOns\Bagnon\libs\AceAddon-3.0\AceAddon-3.0.lua:346
modules = {
}
ToggleFrame = defined @interface\AddOns\Bagnon\main.lua:89
IterateEmbeds = defined @interface\AddOns\Bagnon\libs\AceAddon-3.0\AceAddon-3.0.lua:456
IsBagPurchasable = defined @interface\AddOns\Bagnon\info\bag.lua:36
RegisterAutoDisplayEvents = defined @interface\AddOns\Bagnon\main.lua:221
UpdateFrames = defined @interface\AddOns\Bagnon\main.lua:83
Printf = defined @interface\AddOns\Bagnon\libs\AceConsole-3.0\AceConsole-3.0.lua:69
SetDefaultModulePrototype = defined @interface\AddOns\Bagnon\libs\AceAddon-3.0\AceAddon-3.0.lua:423
SavedSettings = {
}
AUCTION_HOUSE_SHOW = defined @interface\AddOns\Bagnon\main.lua:311
defaultModuleState = true
baseName = "Bagnon"
IsEnabled = defined @interface\AddOns\Bagnon\libs\AceAddon-3.0\AceAddon-3.0.lua:465
Frame = {
}
MAIL_CLOSED = defined @interface\AddOns\Bagnon\main.lua:302
DisableModule = defined @interface\AddOns\Bagnon\libs\AceAddon-3.0\AceAddon-3.0.lua:364
GetPlayerColor = defined @interface\AddOns\Bagnon\components\tooltips.lua:128
BagEvents = {
}
SendCallback = defined @interface\AddOns\Bagnon\libs\CallbackHandler-1.0\CallbackHandler-1.0.lua:87
TRADE_CLOSED = defined @interface\AddOns\Bagnon\main.lua:329
RegisterMessage = defined @interface\AddOns\Bagnon\libs\CallbackHandler-1.0\CallbackHandler-1.0.lua:118
UnregisterMessage = defined @interface\AddOns\Bagnon\libs\CallbackHandler-1.0\CallbackHandler-1.0.lua:181
frames = {
}
HideBlizzardBankFrame = defined @interface\AddOns\Bagnon\main.lua:267
HookTooltips = defined @interface\AddOns\Bagnon\components\tooltips.lua:109
Enable = defined @interface\AddOns\Bagnon\libs\AceAddon-3.0\AceAddon-3.0.lua:313
IsBank = defined @interface\AddOns\Bagnon\info\bag.lua:20
TogglePlayerDropdown = defined @interface\AddOns\Bagnon\components\playerDropdown.lua:70
FrameControlsBag = defined @interface\AddOns\Bagnon\main.lua:131
PlayerSelector = {
}
CreateOptionsLoader = defined @interface\AddOns\Bagnon\main.lua:34
OptionsToggle = {
}
SetEnabledState = defined @interface\AddOns\Bagnon\libs\AceAddon-3.0\AceAddon-3.0.lua:438
ShowFrame = defined @interface\AddOns\Bagnon\main.lua:97
enabledState = true
PLAYER_REGEN_DISABLED = defined @interface\AddOns\Bagnon\main.lua:275
RegisterEvent = defined @interface\AddOns\Bagnon\libs\CallbackHandler-1.0\CallbackHandler-1.0.lua:118
ItemFrame = {
}
ItemSlot = {
}
BagToInventorySlot = defined @interface\AddOns\Bagnon\info\bag.lua:55
FrameSettings = {
}
IterateModules = defined @interface\AddOns\Bagnon\libs\AceAddon-3.0\AceAddon-3.0.lua:451
BagToggle = {
}
BagFrame = {
}
Bag = {
}
SavedFrameSettings = {
}
IsBagCached = defined @interface\AddOns\Bagnon\info\bag.lua:47
BrokerDisplay = {
}
GetArgs = defined @interface\AddOns\Bagnon\libs\AceConsole-3.0\AceConsole-3.0.lua:144
GetBagType = defined @interface\AddOns\Bagnon\info\bag.lua:85
IsTradeBag = defined @interface\AddOns\Bagnon\info\bag.lua:81
TRADE_SKILL_SHOW = defined @interface\AddOns\Bagnon\main.lua:343
OnInitialize = defined @interface\AddOns\Bagnon\main.lua:22
NewModule = defined @interface\AddOns\Bagnon\libs\AceAddon-3.0\AceAddon-3.0.lua:255
SOCKET_INFO_UPDATE = defined @interface\AddOns\Bagnon\main.lua:306
BANK_OPENED = defined @interface\AddOns\Bagnon\main.lua:286
HandleSlashComma
AddOns:
Swatter, v4.2.0 (<%codename%>)
BagBrother, v
Bagnon, v5.2.3
DebugLib, v5.1.DEV.337(/embedded)
Stubby, v5.15.5383 (LikeableLyrebird)
BlizRuntimeLib_enUS v5.2.0.50200
(ck=b6)