I don't know. Matshita may be a mangling of Matsushita. The problem is that the original name is written in Japanese characters, not Roman characters. When one translates the name into Roman characters it can be done in many ways, including (in addition to the already mentioned) Matushita, Matusita and Matsusita.
A Google search for Matshita yields a ton of hits for Panasonic/Matsushita.
Having said all that, I do believe that the official transliteration used by the company is Matsushita:
Scour, are you seeing Matshita on third-party materials or printed right on the box?