After several hours of searching and testing I've found solution for some
problem I know some people already had before with running MySQL 5.x with
Borland Developer Studio 2007. The problem occurs when you have x64 Windows
version and this problem often appears with following error message: "Cannot
load dbxmys30.dll (126). It may be missing from the system path". This
message has nothing to do with system path (ok - sometimes it has), but more
often it's problem with correct version of libmysql.dll library. I've found
that this library won't cooperate with dbxmys30.dll library when you install
MySQL 5.x for x64 version (on Win64 platform of course). To solve this
problem you should also download zipped version of the same MySQL version
you use, but for x32 platform and fetch its libmysql.dll library (bin
directory) and overwrite the old one (for x64 version). Now everything works
fine.
Hope this help.
Konrad Gdowski