I fixed it trying to upgrade to the latest Spring Roo 1.2.1.RELEASE [rev 6eae723]. And sorry, guys, but it really sucks :(
No migration guide, a lot of compilation errors, missing libraries, strange message like "Version is required", "Invalid byte 1 of 1-byte UTF-8 sequence.", which Roo creates itself< wtf required versions for Maven plugin (why it cares???) and such a stuff, that really stops development completely.
I am using Spring Roo for half a year for a big project, and all the time I spend time fixing issues with it, instead of actual development.
DO NOT RELY ON ROO! Once it will just not run, like in my case. Now it starts yeah, but the project is completely broken, updated to unneeded Spring 3.1, and compiles only after a lot of manual intervension!
Here i agree with one guy from Spring Roo forum:
"Please log which file Roo is working on so that errors like this don't prevent us from working totally from doing our work. I have chosen Roo for a quite big project, and as always time is valuable. Now I have been looking for an, to me, unknown error for almost a whole day while my clients need an update to the project asap. But since Roo halts, changes to entities are not processed, and a new version can not be built.
I chose Roo to make things easier, and it really has done a good job with that! But because so much time is waisted when something happens, and the problem is almost impossible to find, the time earned on code generation is soon used on problem hunting..."