OK, this is a long story, but maybe it will help others here and it might even help me.
I have a Thinkpad laptop with a card reader. The laptop has Fedora Linux 14, x86_64.
About the middle of February, in anticipation of getting an Atrix 4G, I ordered a 32 GB Transcend SDHC card, not realizing that it was the regular size, not the microSD size. It arrived on the same day that I got my Atrix 4G, so I quickly realized my error. Nevertheless, I thought I might just keep it and use it with the laptop. Unfortunately, no matter what I tried, it mounted read-only. No utility could write to it, not even as root. Eventually I tried it in a couple of Windows computers owned by friends. One computer couldn't see it at all and the other reported it as defective. So I sent it back to Amazon (still waiting for the refund).
Reading this thread I decided to buy another 32 GB Transcend, but the correct form factor this time. I bought it from Amazon. It arrived today, including an adapter to use it with the laptop.
I tried mounting it in the laptop first (using the adapter), where I got exactly the same problem as with the first Transcend SDHC card. It automounted fine, but read-only. Nothing can write to it, format it, or touch it, whether as root or otherwise. gParted reported it as formatted vfat, the same as the first Transcend card. Since it is vfat it can't be a permissions issue.
Then I put it in the phone. When I inserted it the phone emitted a ringy tone, and I could open a browser to see the device. However, being unfamiliar with Android, I was unable to figure out how to copy files to it. I tried to connect to the phone with the laptop via Bluetooth, but Bluetooth could not send any files to the phone. It was also unable to browse the phone.
Finally, I connected the phone and the laptop with the USB cable. This time the phone appeared on the laptop as a storage device and I was able to see the microSD device with a file browser on the laptop. However, I was unable to copy files to it from the laptop. The error messages were that the device did not exist, even though the Fedora file browser saw it and opened a file browser window.
Then I gave up on seeing the device with the computer and decided just to concentrate on making sure it was read-write on the phone. But when I went back to the phone I was unable to open a browser window to see the device any more. I even powered down the phone and restarted it, but the device no longer mounts at all. I still get a ringy sound when I insert or remove the card, though.
Is the problem that yours truly is an idiot with Android? Quite possibly. Is the problem that the card is defective? Also very possible.
Should I have bought the Dane Electric card or the Sandisk card mentioned above? Well, I have never heard of Dane Electric, but I have definitely heard of Sandisk and the company leaves a bad taste in my mouth. A couple years ago I bought a Sandisk USB flash drive and discovered that they had put a rootkit on it so that it would always pop up a file browser when inserted. The file browser has Sandisk plastered all over it with lots of hype about how lucky you are that you bought a Sandisk device. You cannot remove the file browser even by reformatting the drive. I don't know if other Sandisk products still have their rootkit file browser on it, but any company that thinks their desire to plaster you with their advertising is more important than your need to use the device is not a company that I want to do business with.
So before I send the second Transcend card back to Amazon, does anyone have any thoughts or suggestions? Note that informing me that I am an idiot will not help, as that is pretty understood already. What might help are suggestions for things to try to see if I am just doing the wrong things to get the card mounted, on either the Atrix 4G or the laptop.
It would also be helpful if anyone here bought the Dane Electric card and has it working (or not). Or any other 32GB microSD card.
And thanks for reading this long story of my travails.