I confirm this problem on kubuntu 10.04.
After editing a few iamges (jpeg, not raw) digikam uses more than 400 mo and get's extremely slow.
Closing and restarting digikam solves the problem, but only for a few minutes.
I have been using digikam during 2 years on the same hardware (always on ubuntu) and never experienced before this kind of problem.
I confirm this problem on kubuntu 10.04.
After editing a few iamges (jpeg, not raw) digikam uses more than 400 mo and get's extremely slow.
Closing and restarting digikam solves the problem, but only for a few minutes.
I have been using digikam during 2 years on the same hardware (always on ubuntu) and never experienced before this kind of problem.
Tell me if you need more info.