Currently im working on an image of a dojikko, that does what a dojikko usually does. It falls over anything, causing unwillingly trouble to everyone. I overdid it a little, as i currently have around 150 layers and inkscape gets horrible slow. But at least i can hide the layers i don't work on, which gives more speed, even if hiding some layers takes a good while. The itself has grown up to 15 MB.

An more or less failed export is visible on wikimedia commons: http://commons.wikimedia.org/wiki/File:Dojikko.png
(guess i have to export some layers separately and combine them later with gimp)

wow!

Currently im searching for a solution to import layers from one svg file to my current work. Since i split up my drawing (at least the right figure), since editing on my machine got to slow, to be comfortable. But everytime i try to import something the layers got ignored and get represented as groups. Some way to import layers or convert groups to layers?

"wow!" is right!

Well yes, you can "convert" groups to layers, but not like automatically. You'd have to create new layers, as many as you need, or as many as you have groups. Ungroup, then just select each group and move into the desired layers.

I was just playing around with trying to import layers. I don't know why Inkscape doesn't have such a feature as importing layers, and I haven't yet explored whether it has been requested as a new feature. But imo, it certainly should be.

Another idea might be to select each layer, copy and paste into newly created layers in the target doc. Actually this might be a better option for you, because you would be handling smaller portions. I just imported a 250 kb image consisting of 8 layers, and it took....probably about 3 minutes to import, although I didn't time it. So by copying one layer at a time (or technically copying the content of one layer at a time) you only have to wait for that small portion to paste in. However, note that it might be hard to get everything aligned properly, especially if you've done a lot of clipping.

I hope this helps, but also wish there were a better solution. Maybe someone else will have a better idea? Good luck

Thanks for the "wow" Guess the best solution available will be this bug-report: https://bugs.launchpad.net/inkscape/+bug/502075

At least i can restore the layers, since it is hard to copy 70 layers or so by hand without making a mistake.