strange problem

hi all I'm italian.
I have a terrible problem to my vr500. I use as software:
http://parnass.org/tk500/
and as hardware:
http://users.libero.it/stesella/interfaccia.htm 
 I have never had problems and I have always succeeded in writing and
to read from the vr500, but I don't succeed anymore all of a sudden in
making to converse the receiver with my pc, the hardware function very
well the tension on the electronic components is good. I don't know
more thing to do, i can't even anymore the reset if I try to write the
data in the VR.
while first when everything worked resetted that was a joy. it is also
difficult to explain for me, but I have also tried ADMS3 with any
result. it is not moved anything. for me it depends on the VR, but
what has happened? please you have some suggestion? thanks very much,
when I will find possible I will answer as soon as possible CIAO and
good listening