Had a strange issue last week with IE 9 display rendering.
Having just built an all-up SharePoint 2010 development environment and while slumming around Central Administration I noticed strange display corruption when hovering over some of the controls on the Ribbon.
This only occured when hovering over a control which had a hover tip;
As opposed to a control using a standard tool-tip;
I also noticed that the stock wait/progress display was looking a bit odd;
Investigating further, I fired up FireFox and Chrome and there wasn’t a problem.
Taking a step back, this was a virtualised environment using Parallels Desktop 8 (latest build) on my Macbook Pro as host, with the guest being standard Windows Server 2008 R2 SP1 with IE 9, all updates installed, but no other client software installed (VS, Office etc).
I’d installed SharePoint using the awesome AutoSPInstaller using the RTM build with slipstreamed SP1, Feb 2012 CU and French/Spanish Language Packs w/SP1.
I’d plenty of other VM’s set up in a similar way and comparing VM configuration, paying particular attention to video controller setup, memory etc yielded nothing surprising.
A shout out to #sphelp provided an answer courtesy of @NaupliusTrevor, who suggested turning off Hardware Acceleration in IE 9 advanced settings;
Enabling software rendering and restarting the browser fixed the issue.