gcc 3.3 operator[] disambiguation

[Alexy Khrabrov <alexy dot khrabrov at setup dot org>]

I switched from gcc 2.95.3 to 3.3 for MICO 2.3.10,
a CORBA C++ implementation, and got this most amazing
error ever:

MS_EntryFactoryImpl.C:101: error: ISO C++ says that `typename T::ElementType 
   TSeqVar<T>::operator[](long unsigned int) [with T = 
   StringSequenceTmpl<CORBA::String_var>]' and `operator[]' are ambiguous even 
   though the worst conversion for the former is better than the worst 
   conversion for the latter

The CORBA Var types precede auto_ptr with the same idea.
What's funny is there's no parameterless operator[] in their
declaration for CORBA Sequence Var template.  A CORBA
Sequence type is like a vector, and the offending line contains
a simple dereference, like seqV[i] so the mere use of it causes
a problem!  I wonder what is meant there by "and `operator[]'"?

Cheers,
Alexy