Tiger and Leopard use Java 1.5 to run Moviestorm; we accidentally released some code in the Moviestorm launcher that required Java 1.6 to run; this is part of the patching system, so cannot be fixed with an automatic patch.
Download
this patch file
In the launcher, select 'Install a file' and choose 'Update patch
(.mspatch)' then browse to the file 'fix-mac-1.7.0-patcher.mspatch'
that you just downloaded, and select it.
Moviestorm should then be able to detect future patches and use them to do updates.