"Class names should be nouns, in mixed case with the first letter of each internal word capitalized. Try to keep your class names simple and descriptive. Use whole words-avoid acronyms and abbreviations (unless the abbreviation is much more widely used than the long form, such as URL or HTML)."
1) On Windows svn cannot change from mg.Java to Mg.java for example, may need to change an intermediate step eg mg to Mg2, commit, then Mg2 to Mg, or find a more descriptive name, for example mg.java to Messages.java
2) the form and panel classes, *have* to have the corresponding *.form file changed together. I think that NetBeans 6.5 can do the refactor correctly, but still need to verify.