Hello ,
Few days ago I run in such problem : just before holidays I bought 8 gb SDHC card by TOSHIBA , then I installed on it CHDK software build 0.5.1-499 / fw 101b for my Canon S5 IS. I tested only if it works , haven't got time to test how works transfers . So card is formated with one partition FAT16 32 MB for CHDK and rest was left untouched . In camera it was no problem full capacity of card was visible and usable . But I made many RAW pictures which are unaccessible now . Vista doesn't work with CRW files , JPG were trasfered whithout problems via camera transfer wizard . Any software and Vista itself don't show CRW files from this card . I tried also external card reader - no succes .
After reading this and some other threads about larger than 4GB SDHC cards I started to worry ,but ......
today --- Tada ...tada ... bingo !!!! I solved my problem !!!
I used Paragon Partition Manager 9 to change primary slots (whatever it is ?) for partition on my SDHC card . By the why PPM 9 mounts by default SD card as a fixed harddrive which is essential for such operation . Primary slot change is data safe operation ,and after that my Vista were able to see whole photo storage space and my valuable 1,5 Gb (about 150 pictures) CRW files are being transfered via card reader to my hdd , now .
The drawback is that probably I'll must reverse whole opertion to use again card in my S5 with CHDK autoload feature but I'll check this later .
For now after 5 min of copying I can confirm that this metod is OK . Copied files are readable ,not damaged ---- a lot work for me to work with them with LightBox Plus photoeditor which is most superior tool for CRW files I've ever found