Uuhandled exception : User breakpoint

[sandeepkavade]

i am trying to test the c dll in vb. but while calling the function it is giving me the follwing error.

Unhandled exception at 0x77f75a58 in Project1.exe: User breakpoint

the call from vb is like:

Dim buf As String
Dim xml As Long
buf = "abcdefgh"
xml = xmlnode_GetXml(root, buf, 10000)

and the code in c is like:
long __stdcall xmlnode_GetXml( XMLNODE xnode, char* pBuffer, long lBuflen )
{
std::string s = ((XMLNode*)xnode)->xml();
long l = (long)s.length();
if( pBuffer && lBuflen>0 )
{
memcpy( pBuffer, s.c_str(), (lBuflen<l)? l : lBuflen );
}
return l;
}

XMLNODE is typedefed as void*
xml file is successfully geting copied into pBuffer. but what is the meaning of the error.