A new Hotfix has been released for Outlook 2007 that solves a whole heap of issues (22 in total).
Amongst others, it fixes a crashing issue that Exchange administrators were facing when importing pst-files via the import-mailbox cmdlet in PowerShell.
Another notable issue that got fixed is that since installing SP2, the Quick Click category was no longer saved.
Since this is a hotfix and not a regular update, you won’t be offered this update via Microsoft Update but will have to request it. You can do this at the information page of the hotfix which also list all the other things that got fixed. If you are not (seriously) effected by any of these issues, it is recommended to wait for the next Service Pack or regular Rollup Update which will most likely contain all these fixes as well.