This has never worked for me. Black screen when launching, then just disappears.
Is the a console command to run it to see what output (if any) it provides?
If tried searching for kasv* but got no program results.
Great looking little app, very smooth transitions and has a really nice "feel" to it. One problem I have encountered is that somehow it is a little picky over whose status update to include. When I look through my FB News Feed with a regular browser (on the N900 or a desktop) I see many status updates that aren't included by Kasvopus. No idea why. Initially thought it may be something to do with FB "Top Stories" and "Most Recent", but that doesn't appear to be the case.
In application manager choose Download - All and type "hot" using the keyboard when the app list opens. You should see "Qt hotfixes" package.
Install "Qt hotfixes"
Reboot the device
Make sure to de-activate (not delete) the Extras-devel repository afterwards from the App Manager so that you don't accidentally install unstable versions of applications as updates.
There is no need to activate Extras-devel, Qt Hotfixes is already in Extras.