Importing dump of huge table takes forever since 5.6.15

[Thomas Mayerhofer]

Since upgrading to 5.6.15 from 5.1 importing dumps takes longer than i can wait. I recognized this during set up of the slave (I know ther would be other ways of setting up a slave, but this led to a basic problem).

When it comes to big tables (5 - 20 GB) the import slows down more and more (disk write speed of then ~100kb/sec).

In the dump all tables are surrounded of disable/enable keys. But nevertheless after a while - far before finishing importing of data - the .myi-file start growing.

Therfore I suspect, that the "disable keys" is ignored by some point.

Any ideas or similar experiences? It´s crucial to us, as for example the process of restore will not work and therefore the backup is useless.

Thanks a lot!