Compiling Code to work in multiple versions

I want to protect my application from being modified/stolen by others, so I need to go through and compile my CF code into byte code. I've done that before and it works fine.

However now I have a delima. With CF8 out I want to make use of the new CFImage tag instead of relying on third party image components that do not seem to work with our main hosting provider.

So I need to include code such as:

If CFVersion is 8
Use CFImage
else
Use third party
end if

However older versions of CF see the CFImage tag and throw a fit, and won't even do anything with the page.

I assume this would also happen if I compiled the code and then tried to run it on an older version of CF as well.

Is there anyway I could work around this, or do I have to tell everyone "Too bad upgrade to CF8" ?