@zisoft:
I really can't figure out what's the reason for the behaviour.
After installing some of my plugins in the new installation, the lag reappeared. -Okay, expected behaviour-
So I removed the plugins one by one, but it's still there now, even without any other plugins installed!
PS: What puzzles me the most is the fact, that calibre is acting normal if I deactivate the improved driver.
PPS: as I wrote in #26, if I disable the #read column, everything is fine.
But this feature is one of the reasons why I use the improved driver.
+ I deleted all custom columns, didn't install any other plugins but the delay is still there.