Whenever I click on the Symbols button in the Algebra window I get a program crash.  Just before the program is shut down there is a message box with the message: "Error: Access violation at 0x0047A941 (tried to read from 0x8F000008), program terminated."  This is on a registered copy of UltimaCalc Pro, v4.1.965 running on Windows 7, 64 bit.