EVault 11.0 Virtual Vault never show content

I;m in the beginning of migration to EVault 11.0 and Virtual Vault configured with "Never show content" for Show Content in Reading Pane in Desktop policy. What I found that on two different PCs I get different results for the same user in Outlook 2010. On one PC I get short message with yellow warning that this is not original message, but on two other PCs I tested it, full message preview is happening. Can anyone tell me what can it be? Thanks.