Great, last test:
web.mit.edu/mgg6/www/rockbox-clip+-275v.7z
This slightly raises the voltage for SD cards, but not as much as the previous patch. It should have better battery life. If you don't have any trouble, let me know and I'll commit it in a few days. If you have problems, I'll just go with the previous patch, even though battery life will be a tiny bit worse.