Thanks Hadron.
I'll partition the new card - that's not a problem. (The annoying thing is how much I've forgotten since I originally rooted my phone!)
OK - so on the new card, I need two partitions. 31GB of FAT32 and then 1GB of EXT2 sound about right? (EXT2 sounded best because of the lack of journalling, which sounds like too much work for a mobile phone.)
Re apps. Is the backup option in Clockwork the same as a nandroid backup. I hope so!
Restoring them: It seems like XP can't read EXT partitions, and when I boot to a Ubuntu CD, I don't have write perms to any of the drives on my PC. How do I copy from one SD card to another?
If I can't restore all the apps, and instead do a fresh install of them, that's not too bad - it would be a good way to get rid of accumulated crud that I've installed and uninstalled over the months.
Of course I want to get the new card to work, but at the moment just getting the phone to boot would be a victory - so onto the old card:
Today I put the 8GB card into a card reader in my PC. I booted into Ubuntu from CD and tried to take a copy of the whole card. I couldn't because of being unable to write to any of my NTFS hard drives.
I might have damaged my card because when I was in Ubuntu, I did get a lot of USB hardware errors, and I didn't safely eject the card. (I figured that as I wasn't writing to the card, I didn't need to worry about safely ejecting - or at least that's how it is in Windows.)
I put the card back in the phone and that's when it started looping. After about an hour, I went into Clockwork recovery and deleted the cache (I thought it was the dalvik cache). I rebooted. After a half hour of looping, I went back into recovery and deleted the dalvik. I rebooted, it looped.
I've also tried rebooting with no SD card. Would you expect that to work? (It didn't!)
No recent backup, I'm afraid.
Thanks, Richard
I'm afraid you'll need to repartition the new card. For one thing, the A2SD tool will be expecting the second partition to be ext, so with only one partition I don't think it will work. Plus everything else you want to store on SD (photos, music, Titanium or Nandroid backups, etc) will need a fat32 partition. In fact it's wasteful to make the ext partition too big, since it isn't used for anything but app storage (and optionally dalvik cache).
Secondly, you'll need to get your apps off the ext partition of the old card onto the partition on the new one. The simplest way of doing this is to do what Rasta said: take a nandroid, copy that to the ext partition of the new card, then restore the nandroid.
So it's no surprise that the phone wouldn't boot with the new card. The question is why won't it boot with the old one back in? So did you do anything other than change cards, try to boot, change back? And while we know you didn't take a nandroid, how recent are your app and data backups? And just to be sure, have you tried just removing the card, checking the contacts are clean, and replacing, just in case it wasn't inserted properly?