I have the same problem. I found in a different forum (tek-tips)a solution from user "pccal" (TechnicalUser) 6 Jan 09 13:58- He said
The file version of your client RCC software should be 2.4.358.6.61 (Java 1.6). & the Voice Mail should be running CP 31.10.31.22. with the RCC server sofware 31.10.28c. he said it fixed the problem. I will try the update.