Hello,  I've done some experiments and found that the function to create the parallelipid don't work in my 32 bits pc wtih gcc version 3.2.3 (Red Hat Linux 3.2.3-59).  But in another with 64 bits and gcc 3.4.6 (which hasn't a visualization tool)(Susana's pc) it works, or at least don't return any error message. When I run the macro file, it aborts and return this message: ***** COMMAND NOT FOUND </gate/collimator/geometry/setDx 100. mm> *****   Can be the problem be the compiler? The visualization tool is not the problem I've tried to run the macro with the visualization enabled and disabled and the error occurs anyway. And I've also done the gmake clean and again gmake, but when I've tried the macro, the error was the same. I really need to solve this problem (quickly)...  Thank you very much for your help.  Best regards, Gilberto Almeida <div>Instituto de Biofísica e Engenharia Biomédica Faculdade de Ciências da Universidade de Lisboa Campo Grande 1749-016 Lisboa, Portugal</div>