strange error message in g++ 4.1.0 but not in 4.0.2

In the following code: __ struct TSigRef : public DObject { . . . friend void CDPTSigRef (PutGetFlag pgf, ASN1* cid, address varAddr, bool baseCDP=false); virtual void CDP (PutGetFlag pgf, ASN1* cid,

Re: strange error message in g++ 4.1.0 but not in 4.0.2

In the meantime I have found out that the error message disappears also if I omit the (anyway redundant) address cast in line 56. That's sufficient to solve my problem, although I have no idea what this has to do with the error message, but I have given up hope to understand all secrets of the C++