Java plug in fatal error

Hi there. Can someone please give me some advice as to how I can resolve this problem.

From time to time when I am browsing certain web sites the following screen is displayed as follows:- Java plug-in fatal error.'Several Java Virtual Machines running in the same process caused an error'

How can I rectify this error please. Thank you in anticipation.

[376 byte] By [cg9935a] at [2007-11-27 8:35:13]