A hotfix for 0.5.0 on both handhelds, delivered over Wi-Fi only: open Settings > Update on your RG DS or RG DS Plus and it finds 0.5.0.1. There is no new SD card image; a fresh install is 0.5.0 from the 0.5.0 release, then this update.
🎤 The microphone hears you on time (BananaDS)
BananaDS gave every game the microphone about 1.3 seconds late, so a blow or a word arrived long after you made it, and games such as The Legend of Zelda: Phantom Hourglass seemed not to hear you at all (#14). It now reaches the game in about 50 ms. Tested on the RG DS Plus: Phantom Hourglass's candles go out with a real blow.
For microphone games, play with BananaDS: Settings > Nintendo DS > Emulator, or for one game, X on it in the library > Emulator > BananaDS. DraStic (SuperDrastic, the default) has no real microphone, only a "blow" key.
The microphone log (banana/logs/bananads/bananads.log) now says every 5 seconds how far behind the game hears it, for reports.
🎮 DSi games with your own DSi's BIOS (BananaDS)
DSi games and DSiWare (.dsi, .cia) run with the BIOS dumped from your own DSi. BananaDS used to look only for dsi_bios9.bin and dsi_bios7.bin in lowercase straight in bios/, so a dump named DSI_bios9.bin, or kept in a DSi BIOS folder, was missed and the game stopped at a white screen (#98). Any case and the other usual names (bios9i.bin, biosdsi9.rom, nand.bin) now work, in bios/ or a folder inside it.
Without your DSi's NAND (dsi_nand.bin, optional), a DSiWare game came up in Japanese: it now uses its own region's languages. Tested on the RG DS: 3D Space Tank and Flight Control, in English, with and without the NAND.
A .cia packed as .7z must be unpacked first: the library lists .dsi, .cia, .nds and .zip.
Update
Settings > Update > Check for updates, then Download and Install. Your games, saves and settings stay as they are.