Thanks for the info, in fact I had to fix myself the plugin suggested by your link (see stephenlo link) re-inserting the original .tiff image in place of that provided by the modified plugin.
Let me summarize what I did and worked (from your link plus my fixes):
1. download the 5230 plugin from
http://www.facebook.com/l.php?u=http%253A%252F%252Fwww.4shared.com%252Ffile%252F 186815418%252F858fd09c%252FNokia5230_isync_plugin2v1pho.html&h=3c5ba33f8939bf30c255341d63d7bec2&ref=share; this is the original plugin for Nokia 5800 modified by stephenlo to work with 5230
2. download the Nokia original plugin for Nokia 5800 from
http://www.nokiausa.com/get-support-and-software/software/isync/compatibility-an d-download
3. in the finder open both the downloaded plugin package,
Nokia5230_isync_plugin2v1.phoneplugin, and the original plugin package
Nokia5800_XpressMusic_isync_plugin2v1.phoneplugin, open both their Contents/Resources folder
4. remove the Nokia5230.tiff file from the 5230 plugin and replace it with the Nokia5800XpressMusic.tiff file by copying it from the 5800 plugin
5. modify the
ModelIcon String in the +Root/Nokia5230/Services/0/Service Properties+ (in the 5230 plugin Contents/Resources/MetaClasses.plist) from Nokia5230.tiff to Nokia5800XpressMusic.tiff, to match the new file name (you can use the Property List editor free from Apple - or the free application TextWrangler)
6. set the modified plugin into your home/Library/PhonePlugins folder (if PhonePlugins does not exists just create it).
Now you should be able to sync Nokia 5230 with your Mac.
Piero