Can't undelete files deleted by LAN share

It often happens to me that when I try to undelete certain files that I
removed from another computer on the local network, the unedelte software
does not find them, except maybe a couple of times out of ten.
I tried several free and commencial (mostly demos) applications like Recuva,
Active@Undelete, Glary Utilities, R-Studio 3.5...
What I do is, exactly:
1) From Computer B I delete a file located on computer A.
2) After realizing I made a mistake I go to PC A and (as I know the file is
not on the trash can) I scan the disk (thus locally)... but in most of
cases the undelete utilities come out with thousand of files I erased years
ago (and that have no chance of being restored) BUT no trace is found of the
file I've just deleted!?!
This is particularly annoying as files deleted by a network system do not
finish in the trash can, as you know, so they're lost and that's all.

Thanks for reading this.