Andrus,
You have to scan through all VCXs in the project looking for the classes that are marked OLEPublic (rows where Reserved2 = OlePublic). You will find the same classname in two different classlibs and that is what is throwing this error.
If you are using PRG based classes you'll have to root out the duplicated DEFINE CLASS code.
>OLE error code 0x8002802d: Name already exists in the library
>
>How to fix this error ?
>How I can determine which name alrady exists ?