Quickly scrolling down in a category has occasional 'jumps'

Open any category, like Accessories, select an entry, then hold on to the down arrow.

You will occasionally see a 'jump' where the highlighted entry is displayed at the top of the window. Doesn't affect function, just cosmetics.

If you then hold on to the up arrow, you don't see a similar problem. Only when scrolling down.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: software-center 5.1.14.2
ProcVersionSignature: Ubuntu 3.2.0-23.36-generic-pae 3.2.14
Uname: Linux 3.2.0-23-generic-pae i686
ApportVersion: 2.0.1-0ubuntu1
Architecture: i386
CheckboxSubmission: 9a284f3f6b4f7829abbe27ad9573a709
CheckboxSystem: 3935143777c965daaa64b51f0134f712
Date: Wed Apr 11 16:16:54 2012
EcryptfsInUse: Yes
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Release i386 (20110422)
PackageArchitecture: all
SourcePackage: software-center
UpgradeStatus: Upgraded to precise on 2011-11-05 (157 days ago)