Thanks for sharing.
1) Some people get issues with SD Cards on Nook HD and HD+ and some don't.
2) Android 4.0 uses MTP which is the MAIN reason for problems. Are there B&N bugs on top of that? Perhaps. Not sure.
3) Yes, there are some SD card related issues. Usually ones that are gradually being fixed.
4) You're the first person I've seen who had the problem with 2 GB files.
Just adding these data points to give a more accurate picture.
I wonder if it's possible that there's a configuration which causes the OP's device to format its card as fat16, or see it as such? A fat16 partition has a 2 gig file size limit. I have a hazy memory that there's a situation in linux where a fat partition can default to fat16 in some cases of a borked disk signature.
five writes "Android 4.0 uses MTP which is the MAIN reason for problems. Are there B&N bugs on top of that? Perhaps. Not sure."
Certainly that's a source of problems, in particular since it confuses a lot of folks about what they expect to see when they connect their HD or HD+, and because MTP is buggy.
I'm one of the folks who's seen sdcard access slow down the device at irregular and seemingly random intervals, across a range of cards from 8 to 32 gig and from Sandisk as well as other flash manufacturers.
"Yes, there are some SD card related issues. Usually ones that are gradually being fixed."
What is the evidence - from BN - that these are being fixed as opposed to experimented on using customer devices and the auto-update mechanism to explore the problems? While it's clear that BN is working on them, we don't know that from any BN statement, and to date I disagree that fix is the relevant term.
We know about the changes primarily thanks to the dedication of the XDA developers who are looking at the kernel source and kernel behavior and seeing changes to how SD cards are addressed.
Many folks, here and at XDA, are reporting that the 64 gig high speed cards are very flaky. I don't remember if the official spec states that 64 gig cards are supported.