Solution was:
To change registry jkey on Win2k


Before:
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSDTC\MTxOCI]
"OracleXaLib"="xa73.dll"
"OracleSqlLib"="SQLLib18.dll"
"OracleOciLib"="ociw32.dll"

After:
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSDTC\MTxOCI]
"OracleXaLib"="oraclient8.dll"
"OracleSqlLib"="orasql8.dll"
"OracleOciLib"="oci.dll"