I really hope your Unmounting the SD card before your removing it.
Menu > Settings > SD & Phone storage > Unmount SD card
Remove the old and install the new
There should be no reason to boot into recovery.
To copy files....
Plug in your USB cable (from your PC)
Drag down the notification bar (should say "Charge only")
Select "Charge only" then on the next menu choose "Disk drive" and press Done
Your PC should open a window showing the contents of your SD card
Drag down the notification bar (should say "Disk drive")
Select "Disk Drive" then on the next menu choose "Charge only" and press Done