Still having problem when using Recuva portable version.
But it can operate well in WinXP SP3, and the problem exists after I upgraded my computer to SP3 until now.
Really hope that can be fixed.
By the way, although it is not really related to this, but other software from other company will have the same problem, for example, GIMP.
Now what can I do is to think carefully whether I need to delete the files I don't want...