Informatica 9.1HF4 has been released to shipping and is available immediately for download.
Informatica 9.1HF4 release highlights includes the followings:
Informatica 9.1.0 HotFix 4 Release Notes (English)
Please use the following link to download the hotfix - Informatica 9.1 Hotfix 4 Download
For Product Documents regarding 9.1 HF4 (all Langunges) and other 9.1 Hotfix versions, you can download them from the
Product Document DVD at Product Docs