My /usr/share/hal/fdi/policy/10osvendor/20-storage-methods.fdi has a "strlist">flush</append> entry under <!-- allow these mount options for vfat -->. However, the "flush" mount option is not being used according to /etc/mtab but it is available.
cat /etc/mtab:
/dev/sdc1 /media/KINGSTON vfat rw,nosuid,nodev,uhelper=hal,uid=500,utf8,shortname=mixed 0 0

mount -o remount,flush /media/KINGSTON
cat /etc/mtab:
/dev/sdc1 /media/KINGSTON vfat rw,nosuid,nodev,uhelper=hal,uid=500,utf8,shortname=mixed,flush 0 0

I am running Mandriva-2009.1, KDE-4.2.2, Kernel-2.6.32-2 & HAL-0.5.12 & read somewhere that KDE allows the mount options to be set only on a per-volume basis, not per-filesystem.
If that is true, maybe it isn't possible to have a "global" flush mount option that would apply to "All" vfat filesystems when using KDE4.

Anyways, if anyone has a good solution or workaround, I'd appreciate hearing from you. Also, is it true that HAL is being replaced by a new device manager called "DeviceKit".??
If so, I hope it can be disabled without disabling "X" like my HAL does. I tried disabling HAL & couldn't even login to KDE4.

Thanks for reading this post.

I finally figured out how to force KDE4 to mount all my usb-sticks with the vfat filesystem using the "FLUSH" mount option. All I had to do was create a entry in my /etc/fstab file for the usb-stick & add both the FLUSH & NOAUTO mount options like the following:

/dev/sdc1 /mnt/pendrive vfat rw,noatime,umask=000,utf8,uid=500,shortname=mixed,flush,noauto,users,exec,suid,dev 0 0

Contrary to what I read, KDE4 will still automount this pendrive even though it has a listing in the fstab file. This is probably due to the "NOAUTO" option. I guess KDE4 automount reads mount option from the /etc/fstab & then adds its own mount options if they are missing. There is a system of priorities when it comes to applying mount options.

Here are some problems with this solution:
1.) usb-stick drives (pendrives) that are not formated with the vfat filesystem & are identified as /dev/sdc1 by Linux will not automount.
This is because the FLUSH mount option is only valid with vfat....You will have to manually mount /dev/sdc1 with an ext2/3 filesystem on it.

2.) If you plugin multiple usb-stick drives your vfat usb-stick may not get identified as /dev/sdc1 by Linux & it will not get the FLUSH option.
It will only mount with the regular automount options.

If anyone sees more problems with my workaround feel free to respond.