Windows 7: Many junction points broken under %userprofile%

all the junction points under %userprofile% got broken. when double-click, explorer prompts "XXXXX is not accessible". however the target folder (e.g. "%userprofile%AppData\Roaming\Microsoft\Windows\Recent") can be opened normally;
at the same time the junction point can be accessible in cmd.exe, however all items in the target folder can not be shown in this case.
please help me to find out what's the problem and how to fix.

Can you tell me what file windows is saying is inaccessible

not file, they are the folders:
<JUNCTION> Application Data [C:\Users\bin_li\AppData\Roaming]
<JUNCTION> Cookies [C:\Users\bin_li\AppData\Roaming\Microsoft\Windows\Cookies]
<JUNCTION> Local Settings [C:\Users\bin_li\AppData\Local]
<JUNCTION> My Documents [C:\Users\bin_li\Documents]
<JUNCTION> NetHood [C:\Users\bin_li\AppData\Roaming\Microsoft\Windows\Network Shortcuts]
<JUNCTION> PrintHood [C:\Users\bin_li\AppData\Roaming\Microsoft\Windows\Printer Shortcuts]
<JUNCTION> SendTo [C:\Users\bin_li\AppData\Roaming\Microsoft\Windows\SendTo]
<JUNCTION> Start Menu [C:\Users\bin_li\AppData\Roaming\Microsoft\Windows\Start Menu]
<JUNCTION> Templates [C:\Users\bin_li\AppData\Roaming\Microsoft\Windows\Templates]

besides, if I recreate the junction point via System internal tool "junction", it can work.

Is junction a folder on your system

You are not suppose to even be able to access those Junctions, you should be getting an Access Denied message.

Just to second what logicearth said, you're not supposed to be able to access them via explorer. Otherwise, programs such as backup ones will recurse such folders especially under %appdata% repeatedly and infinitely.

thank u all for help!

Where did the "all users" junction point come from? And how come there are junctions for Music, Pictures and Video folders as well?