MySQL libmysqld.dll v5.1

I have an application that I developed using libmysqld.dll Ver 4.1?
It runs perfectly.

I have recently updated the headers etc and tried it with Ver 5.1

If I use the strings in the documentation example here:
http://dev.mysql.com/doc/refman/5.1/...rary-init.html
at the library intialization stage mySQL_library_init()
It will complete the initialization, but with an error = 1

If I then add a path ie:
"--datadir=F:\Documents and Settings\All Users\Application Data\MySQL\MySQL
Server 5.1\data"
... it hangs.


But, if I use these strings:
"this_program"
"--datadir=F:\Documents and Settings\All Users\Application Data\MySQL\MySQL
Server 5.1\data"
"--skip-innodb"
"--skip-bdb"
"--skip-networking"
"--language=./english"

... it intializes with error code = 1

In Fact there seems to be no combination that does not result in error code = 1

What am I missing here?

Any help would be greatly appreciated