Thanks. I found another bug though.
If 2 games, for GB and GBC share the same name, it messes up with savestates. For instance:
1. Get 2 ROMs, Wario Land II (USA, Europe).gb and Wario Land II (USA, Europe).gbc
2. Open up BizHawk
3. Load Wario Land II (USA, Europe).gbc
4. Make a savestate using the hotkeys for it. This should make a file called Wario Land II (USA, Europe).Gambatte.QuickSave1.State
5. Load Wario Land II (USA, Europe).gb
6. Use hotkey to load the 1st savestate. This will give an error, and crash BizHawk:
System.InvalidOperationException: Savestate buffer size mismatch!
at BizHawk.Emulation.Cores.Nintendo.Gameboy.Gameboy.LoadStateBinary(BinaryReader reader)
at BizHawk.Client.Common.BinaryStateLoader.GetLump(BinaryStateLump lump, Boolean abort, Action`2 callback)
at BizHawk.Client.Common.BinaryStateLoader.GetCoreState(Action`1 callbackBinary, Action`1 callbackText)
at BizHawk.Client.Common.SavestateManager.LoadStateFile(String path, String name)
at BizHawk.Client.EmuHawk.MainForm.LoadState(String path, String userFriendlyStateName, Boolean fromLua, Boolean suppressOSD)
at BizHawk.Client.EmuHawk.MainForm.LoadQuickSave(String quickSlotName, Boolean fromLua, Boolean suppressOSD)
at BizHawk.Client.EmuHawk.MainForm.CheckHotkey(String trigger)
at BizHawk.Client.EmuHawk.MainForm.<ProcessInput>b__130_1(Boolean current, String trigger)
at System.Linq.Enumerable.Aggregate[TSource,TAccumulate](IEnumerable`1 source, TAccumulate seed, Func`3 func)
at BizHawk.Client.EmuHawk.MainForm.ProcessInput()
at BizHawk.Client.EmuHawk.MainForm.ProgramRunLoop()
at BizHawk.Client.EmuHawk.Program.SubMain(String[] args)
7. Optionally, make a savestate (different than the first one; savestate 2 works) with Wario Land II (USA, Europe).gb. Note the file name (Wario Land II (USA, Europe).Gambatte.QuickSave2.State)
8. Go to the file explorer and rename Wario Land II (USA, Europe).gb to something else like Wario Land II (USA, Europe) gb.gb
9. Make savestate 1 using hotkeys. This still overwrites the GBC savestate 1 instead of making a new state, despite the file name change. ie, it still saves as Wario Land II (USA, Europe).Gambatte.QuickSave1.State
Please help?