Just for the records I copy here a response I've received from an authorized source about this topic:
You can go the other way and force Acrobat (and when I say Acrobat I mean both Acrobat and Reader) to not go online, but you can’t tell it to only go online.
The revocation checking algorithm is a bit convoluted, but it boils down to a long list that describes the order in which Acrobat will do revocation checking. The concept is look for a valid response in the first location, stop if you find one or continue down the list if you don’t find one. If Acrobat looks locally and finds a CRL, it will check to see if it is valid. If it’s not, then it ignores it and moves to the next location on the list.
If you really want to test the Seed Value while the computer is offline you would need to clear the CRLCache prior to initiating the signing routine. Also, if you opened a signed file that had the revocation embedded, and it’s the same CRL that you will be looking for, that CRL will have been loaded into memory and used during the subsequent signing operation within the same session. Your best bet is to close Acrobat, take the machine offline, clear the CRLCache (see below), launch Acrobat, open the unsigned file with the Seed Value, and try to sign.
The CRLCache is located at:
Win XP
C:\Documents and Settings\<user name>\Application Data\Adobe\Acrobat\9.0\Security\CRLCache
Vista/Win 7
C:\Users\<user name>\AppData\Roaming\Adobe\Acrobat\9.0\Security\CRLCache
Mac OS X
/Users/<user name>/Library/Application Support/Adobe/Acrobat/9.0_xxx/Security/CRLCache
Saludos,
