Hello Stanislav,
Yes! In fact, this question was just raised in this post! The basic issue is that Shannon's metric can use a log of any base; log-base-e with ln(), or log-base-10 with log(), or log-base-2...
While any base-log can be used, I've never seen the Shannon base-log reported in a paper. But these differences could be why the magnitude of Shannon varies between papers.
Colin