digital signature

Hi,
I use access 2003 sp1. with an mdb/mde.
On one pc we created a certificate and installed it in the client. Created
an med and installed this on the users pc, imported the certificate and
evrything is working.

On my pc I imported the certificate, when I try to link this on an mdb get
this message.""there was a problem with te digital certificate. the VBA
project coult not be signed. The signature will be discarded.

I tried this also on another machine, with the same message as result.

When I try this on the original machine it is working.

Can someone help me?
Abrm