I'm not sure of my exact BIOS version but I'm almost certain it isn't up to date. Thanks for the link.
Also, I'm aware the MMC Replay isn't a 1541 drive emulator - to my disappointment I discovered this shortly after purchasing the unit, as I had expected to use it in that fashion - sure, I would've been better off with a 1541 Ultimate in retrospect, but I've already spent $150... even spent the time cutting out a pretty cartridge casing and everything... gotta roll with what I have for now

Which leads me to my next question: I've caught mention of DFI's and other stuff as I bounce around between threads. Is any of that relevant to me (what's if for)? I.e. are there any workarounds designed to deal with the above facts, or am I really just stuck copying programs to a real 1541 from flash and I should just give it a rest?
My beef is really here: I have piles of software in .T64 format. I want to use these and I'm not sure of the most efficient + working route to get from .T64 file on the PC to something that runs on the real C64. I also noticed in another thread, something about the TNT browser. Not sure if this even works on an MMCR, but it might help me read .T64 files, right? At that point I could at least copy them to a disk, I assume?
If anybody wants to indulge my curiosity, there are a couple of other things, of less importance

- Since I have the MMC Replay... what can I do with the "Replay" part of the device? Anything cool or useful that doesn't involve machine language or anything else beyond the understanding of a "casual" C64-ist?
- Using the MMC Replay for networking sounds interesting. But again, how does this work, i.e. what can it do for me and how is it used? I don't have the RR-Net module but I might go there if I had any idea what I could get out of the investment.
It might seem silly to be asking these questions only after owning the device for 8 months, but hey... I bought the whole unit partially under the misconception it was going to do stuff it wasn't capable of, so better late than never. That said, I've had fun with it and it does serve well one of my original purposes for buying it... which was to run C64-based software synthesizers I could play live during musical performances. Luckily those tend to be single-file programs and I've had no trouble running them directly from the SD card.
Thanks for your input and suggestions,
Owen