WARNING: The exact cause of Vista losing it's memory on your folder view settings has not been found yet. This will just reset them for now to help Vista remember them again. It has been noticed that changing a lot of window folder view settings in combination with some unknown applications settings may be triggering this forgetfulness. Make sure that you do not have a setting in a 3rd party program set to clear the folder view setting cache when it is used. (EX: CCleaner - Window Size/Location cache option under Cleaner -> Advanced)

Reset Folder View Settings :
1. Open the Start Menu.
2. In the white line (Start Search) area, type regedit and press Enter.
3. Click Continue for UAC prompt.
4. In regedit, go to:
HKEY_CURRENT_USER\Software\Classes\Local Settings\Software\Microsoft\Windows\Shell\Bags

5. In the left pane, right click on Bags, and click Delete.

6. Click Yes to the confirmation pop-up window.

7. In regedit, go to:
HKEY_CURRENT_USER\Software\Classes\Local Settings\Software\Microsoft\Windows\Shell\BagMRU

8. In the left pane, right click on BagMRU and click Delete.

9. Click Yes to confirmation pop-up window.

Increase Folder View Cache Memory :
NOTE: This will increase the amount of folders to be remembered for changes to the folder view settings.
OPTION: This is a optional step, but the increase will help ensure that Vista does not forget. Steps 1-9 must be done first before you do this section. If you decide to skip it, them go to step 13.

10. In regedit, go to:
HKEY_CURRENT_USER\Software\Microsoft\Windows\Shell

11. In the right pane, right click on BagMRU Size.
23. Click Modify.

12. Dot the Decimal and type 20000 (folders) and click OK.
NOTE: 5000 is the default number of folders to be remembered.

Wrapping it Up :
13. Close regedit.
14. Logoff and logon,or restart the computer to apply the reset and to let Vista rebuild the registry keys with a clean slate.

Source:

Windows Explorer Folder View settings - Vista Forums

I have tested this and it does to seem to work so far