Currently it is impossible to rename an item number from 123.xx (lower case) to 123.XX (upper case).
Possible workaround of renaming 123.xx (lower case) to 123.yy and then to 123.XX (upper case) results in original value 123.xx (lower case - wrong) !
The only way to solve this is to delete the item (and all related data: Properties, BOM,...) and recreate from zero (if possible). Please make Item Number rename case sensitive aware.
