I referred to the manual and this is operating system specific and even file system specific (in the case of Mac HFS+/UFS.) There is a startup variable lower_case_table_names that can force the creation and testing to lower case, but the default setting for this variable is different for Unix/Win/Mac..., which results in operating system differences. On Unix, the default value of lower_case_table_names is 0. On Windows the default value is 1. On Mac OS X, the default value is 2.
Considering that databases should be independent of the operating systems that they are running on, the above operation was a poor choice by the designers (the naming of tables should be independent of any filesystem properties.)