I finally found a solution applied with version 1.3.1 and higher.
Space consumed on phone (HTC Desire) ... | Old size [MB] | New size [MB] |
... without data, phone only | 2,77 | 1,30 |
... without data, App2Sd | 2,02 | 0,77 |
More background information can be found here: Actionbarsherlock conversation