Windows Mobile Device Center Problems and Missing Features

Hello Everybody.
I have Windows Vista Ultimate and Office 2007 (Retail). My PDA is an
iPAQ6915. I have installed Windows Media Device Center (RTM) and I face the
following problems:
1. The synchronization with outlook is not always done (no error messages).
Specifically, when adding new appointments to my outlook calendar and my PDA
is on its cradle, there are occassions when not all of them are trasneferred
to the PDA. By replacing the PDA on its cradle the problem occurs less
frequently.
2. The file explorer option is very limited in functionality. Although I can
browse my PDA's file contents not all files and folders are shown in the
directory tree. For example the windows directory of my PDA is not shown
(even though I have enable the view of hidden or system files).

Both the above problems did not occur with ActiveSync 4.2 that I previously
used with the same PDA on Windows XP Pro.

Can anyone help please?
Thanks.