We are using Chilkat_v7_9.dll with Delphi 2006. In one site an access violation was happening - caused by some other program which had installed Chilkat_v8.dll. Reinstalling our software resolved the issue for now. Is there some way of ensuring we don't interfere with other apps using a different version of Chilkat and vice versa?
While I haven't tried it myself with Chilkat libraries, you could also look into registry-free COM using an application manifest with the DLL(s) in your application directory. This will only work in XP or newer version of Windows, so if you have requirements to support older OSes then it's a no-go.