I created my prototype with the 1st rev of the Adafruit Data Logger, worked like a charm.
I ordered 25 of them of a project, I received Rev B, no big deal right? Different RTC chip so I swapped the RTC_DS1307 rtc; line to RTC_PCF8523 rtc; That works.
Any SDcard I use initializes no problem but it cannot open, read or create files.
Strangely, it sometimes works.
I am using fresh out of the box Arduino UNO's, Transcend 2GB cards as well as Acumem HC class 10 4GB cards.
Frustrating as I don't know where the problem is so it's hard to fix.
M