Than you for new version, but a have same problems with 3.64 and 256 MB SD card.
I use DSO Nano V1, with 256 MB micro SD card.
With old version 3.62 no any problems with this card, but with 3.64 my DSO Nano is freeze when 256 MB card is in device. When card is removed, no problem. When use 4 GB or 8 GB card, no problem too. Only with small 256 card, DSO freeze. My be support of small card is problem…
The 3.64 version works well with my limited mix of SD/SDHC cards, but it is quite possible that the added complexity of the SD/SDHC auto-detect logic can break compatibility with some cards. Fixing this (if at all possible) is difficult without having access to the specific card that fails.
Your option may be to stay with 3.62 if this 256MB card is what you prefer to use.