What is the MS Excel version?
Excellink communicates using a Java DDE client libary that makes connection with the MS Excel. The problem is that it is hard to pin point where the communication is lost. Is it from ExcelLink, the DDE client library, DDE server on the MS-Excel or Excel itself.
When you lose communication, would restarting the ExcelLink solve the problem? If not, do you have to also restart the MS Excel to resolve the problem?
If you reduce the number of active programs running on your computer to just ExcelLink, MS Excel and (optionally) the TLServer, do you still lose communication often? How long do you run the program before it starts to lose communication?