That message is a stupid thing that .NET does when the manifest isn't updated for a year. It referred to the actual patcher itself, not ISXVG.
Your ISXVG.dll is probably the latest one. The "version" string doesn't really mean anything as they're all going to say 2008.0.0.xxx (with xxx being the build number I use.) I do not update the other three numbers within the compile itself.
However, if you load up ISXVG and do "echo ${ISXVG.Version}" it will tell you the true version ...which should match what is in the topic on IRC (irc.lavishsoft.com, #isxvg).