As of 0.7.17, Plagger still suffers from 'assets trap', that means, you must prepare assets files by yourself (the best way is to download them from its subversion repository).
See Plagger's FAQ for details.
Mainly for Japanese users: you don't need to install older perl (5.8.7) any more, as the latest PPM (build 820 and above), though still with some problems, can handle post-install scripts. You may find lots of older blog or magazine articles which tell you to install older perl, but I believe they are almost *obsolete* now.