After 4 months, here is a new release which includes support for PSP Slim and 3.XX firmwares, the support for 1.50 has been dropped, as new hardware no longer supports it. This also means that you can now use the game in WPA authenticated access points which wasn't possible under 1.50.
This release also includes some small bugfixes, and the fix to avoid the nasty crash which was produced while playing the game with the midi background music enabled, so now you can play while hearing background music without unexpected crashes. It should be really stable now.
Changelog
Code updated to be Slim and 3.XX firmwares compatible
Code updated to 0.5.3 to be able to play on latest online servers
Game crash while playing background music fixed
Bug from last resize of replace trains window fixed
Windows can now be dragged out of screen limits, to be able to see windows which exceded the screen height, such as the patches configuration dialog, just hold square pressed over a window to move it
Place Tree window now is displayed inside screen limits
PSP dedicated server upgraded to 0.5.3
Dedicated server for PSP players have also been updated: