Did you use the service password-encryption command. It seems there was a bug that allowed the Tacacs password to remain unencrypted, but it did not affect radius so if you enter that it should encrypt it.
I checked it on my ASA running 8.3(1) code and it is shown as ***** rather than the actual pw. I guess you should find out when this changed and update to that version or just get the newest version. Sorry this was not an easier fix.
Table of ContentsIntroductionVersion HistoryPossible Future
UpdatesDocuments PurposeNAT Operation in ASA 8.3+ SectionsRule Types
Network Object NATTwice NAT / Manual NATRule Types used per SectionNAT
Types used with Twice NAT / Manual NAT and Network Obje...
Table of Contents Introduction:This document describes details on how
NAT-T works. Background: ESP encrypts all critical information,
encapsulating the entire inner TCP/UDP datagram within an ESP header.
ESP is an IP protocol in the same sense that TCP an...