Really impressed so far with KDE 4.8. A couple on niggely problems though. Firstly, virtuoso-t is using anything up to 85% of CPU. Can switch off nepomuk and this goes away.

Secondly, when attempting to download new splash screens or KDE themes through system settings, getting this error

Hopefuly Eric will see this and will have the answer.

The API error is reported for various issues, and not only for KDE 4.8.0. Google for it and you will see it happening as far back as KDE 4.6.

I tried installing a KDE splash (breathing tux) and that gave me no errors - the theme installed correctly. However, I am logged onto OpenDesktop.org's services (System Settings > Account Details > Social Desktop) and that may be the difference.

One KDE bug report (https://bugs.kde.org/show_bug.cgi?id=285441) for another Open Collaboration Service API error indicates that attica versions before 0.3.0 are buggy in this regard. My KDE 4.8.0 packages come with attica 0.3.0, did you install this?

As for virtuoso, it will eat a lot of resources when it creates its first index of your computer. It will ease down in the end and not hog your system once that is done. But yes, you can disable the Semantic Desktop functions and that will stop virtuoso too.

Eric

Blimey, that was a quick response. And as always, the advice is spot on.
Have now registered with OpenDesktop.org and the theme issue have disappeared. Obviously something within KDE has changed as I have not had to do this previously.

As for the virtuoso issue, I have re-enabled desktop search, but as I was running KDE7.4, I was hoping that the upgrade would not have needed to do the full scan thing again.

OK, had nepomuk enabled now for 6hrs or so. Desktop search file indexing shows up as idle. Hard drive activity is nil as far as any intensive activity is concerned, but virtuoso-t still shows at anything from 85 to 111% cpu time, and both cores running flat out. Any more suggestions or is this another KDE feature?

Hopefully Eric will see this. It's now been 2 days since I upgraded to KDE 4.8 during which time I have left my laptop switched on with an uptime of 2 days 5hrs and a few odd minutes, and virtuoso -t is still eating my CPU time. (Currently sitting at 117%)
Seems the only answer is to disable desktop search.
I know this is not a fault of Eric's, but as he is the resident Slackware KDE expert, was hoping he might have some other suggestions to prevent it happening.
Have followed the advice from the KDE bug tracker and disabled the nepomuk search runner and contacts to no avail, so am open to suggestions.

Open more reports on KDE bugtracker, or visit #kde in Freenode IRC network...

Eric

Finally got time to put up more info. I have this problem sorted now by backing up my .kde folder and logging in anew. A pity, as I would have hoped for compatibility across different releases.