Taking a couple steps back...
Missing indexes is there to give you a place to start with creating indexes that may be missing. It is absolutely not something that you want to use to generate you create index statements that you then just run.
Check the troubleshooting book again, there should be some comments about testing and not just creating all suggestions.
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability