Unmounting SD card makes the Finder slow.

Question

I've noticed that since moving to an Intel machine, unmounting an SD card from an external card reader renders the Finder slow in one particular area - when clicking on any of the icons on the Finder's side bar (both the drives above the horizontal divider, and the favourites below) it will take about ten seconds for the contents of the window to update. A reboot will clear this behaviour, but simply re-starting the Finder will not.
Does this happen to anybody else? If not, perhaps the problem is with my card reader (a cheap "Flash Gear" unit), although this didn't use to happen on my old PowerMac.

Answer 1

STEP BY STEP INSTRUCTIONS TO RECOGNIZE AND IMPORT MTS FILES. (No help from Apple.)
After 4 frustrating hours and about 40 useless minutes wasted on Apple Support chat, I figured this out.
Okay, here are the steps to allow Mountain Lion to see your MTS files on a Panasonic camera SD card and import them:
Click on your camera SD card.
RIGHT Click on PRIVATE icon. (This used to be a folder, now it is a Quicktime logo.)
Pull down command for “Show Package Contents”
Click on AVCHD
Pull down command for “Show Package Contents”
Click on BDMV
Pull down command for “Show Package Contents”
Open the folder called STREAM
There are your MTS files. Select them and copy them to a folder on your hard drive.
Purchase some type of video converter (I paid 30 bucks for Bigasoft Converter and it works.)
Import the MTS files into the video converter and set the commands (This is several more steps, which you will have to figure out.) This will take quite a while for large, High Def files.
Save converted files to your hard drive.
NOW, finally FCP X will let you import and edit your files.
Thanks Apple for adding 12 steps where it should take one. “Log and Transfer” or IMPORT.  You should fix this.
It took me about 4 hours of frustration to figure this out. Apple support chat service was no help at all. The girl in chat had no understanding of video files.
Thank you Apple, for hiding these files behind your Quicktime logo, thanks for adding extra steps and decreasing productivity. I've been using Macintosh computers since 1987. I would not own a PC, but Apple is not what it used to be. Why would you not just let the .MTS files show without hiding them?