If I had to guess, I'd say your issue wasn't the size of the disk. There is no practical difference between a 40MB and a 2GB partition from the computer / systems perspective. 2GB is the delineation for size related differences.Yup, I sort of assumed that was a given... worth mentioning though!
I was basing that advice on my experience with a BlueSCSI V1 in a Classic, which really hated 1GB+ disks on certain SD cards. Again, yours is useful info worth adding.