If you happened reset your Scratchbox target or remove *-dev packages, you may need to redo the target setup steps manually, as described in:

http://wiki.maemo.org/Documentation/...l_Installation

I suggest you execute the steps starting from the one called "Switch to x86 target, install the devkits, etc and fakeroot into the target, install the minimal rootstrap and finally the Maemo development files. " (for some reason they didn't number the steps)

Alternatively, if you think doing all that is too much, you may try the quick fix (run this inside each target):