Ok, I have found it!

Oracle8iDialect overrides a method "getCrossJoinSeparator":

	@Override
	public String getCrossJoinSeparator() {
		return ", ";
	}

Oracle 8i does not support ANSI "CROSS JOIN". From 9i "CROSS JOIN" is supported. I have overriden "getCrossJoinSeparator" method in Oracle9iDialect to return original value from org.hibernate.dialect.Dialect class:

public String getCrossJoinSeparator() {
	return " cross join ";
}

It works now with ANSIJoinFragment and Oracle 10g database.

Can someone add a fix to Oracle dialect class?