Usually this message will only appear if you have the peer config missing on the PIX side.
Note: "Every static crypto map must define an access list and an IPsec peer. If either is missing, the crypto map is considered incomplete and any traffic that has not already been matched to an earlier, complete crypto map is dropped. Use the show conf command to ensure that every crypto map is complete. To fix an incomplete crypto map, remove the crypto map, add the missing entries, and reapply it."
So try checking out with the "show config" if you are missing any of that.
Additionally, the following shows the minimum required crypto map configuration when the security associations are being manually established on the PIX:
crypto transform-set someset ah-md5-hmac esp-des
crypto map mymap 10 ipsec-manual
crypto map mymap 10 match address 102
crypto map mymap 10 set transform-set someset
crypto map mymap 10 set peer 10.0.0.5
crypto map mymap 10 set session-key inbound ah 256 xxxxx
crypto map mymap 10 set session-key outbound ah 256 xxxxx
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...