Define dropped voicemail. They are lost, partial recordings, etc?

Recordings are kept in the AVDAP folder. The best way to extract them is through a Voicemail Save. Operations\Database Operations\Voice Processor Save. Choose Voicemail and check mark the boxes below. The next page will allow you to choose which mailboxes to back up. Afterward, open up the files in the save location. An N denotes new messages. An S denotes saved messages. They are in R24 audio format. I have an R24 to WAV converter if you need it.

This may not be the solution you need. It depends on what you want to do.