Problem when TBportable is launched on French 64bits X7 or W8.1

I have been using TBportable for 8 months now on both a French XP SP3 32bits and a English W8.1 32bits without problems.
Then I tried to use it on my new French W7 64bits computer and a French W8.1 64bits one and I have problems: Some of the folders containing mails do not show on the left side directory tree of the program. The folders and mails are always on the USB stick but they simply do not appear. When I run again TB portable on one of my 32bits systems they re-appear...
The same TB portables ran on 2 different English W7 64bits computers without problem ....!!
Can anybody help? I am currently using my TB portable on my French W7 64bits through an XP mode virtual PC ... : It is not sustainable in the long run !