Greyfox,
Though I no longer use Spybot S&D's immunizations myself, it's for other reasons such as performance, not conflicts, since no technically competent AntiSpyware product has such issues more than transiently in this day and age.
In truth, the Spybot S&D Immunizations are nothing but large lists of entries that Spybot adds to the Restricted sites & Cookie blocking of Internet Explorer, Windows Hosts file and the less visible ActiveX 'Kill Bits' portion of the registry. None of these are hacks, though they were never intended to contain many thousands of entries, which can result in performance issues under certain circumstances.
The real problem here is that like many attempts at turning a simple AV scanner into 'Anti-Spyware' before it, AVG is dumb. It simply scans for the existence of these entries in the registry and makes no attempt to test whether they are defined to 'block' or 'allow', so if it's there it must be bad. This is dumb because the values that differentiate block from allow are standardized and well documented by Microsoft, so a program that can't tell the difference is simply badly designed.
AVG is simply making the same stand as most suites today, that they have all the protection you need so you should remove all other products that perform the same or similar functions. Though I agree with this in principal, you must closely evaluate how well the suite performs all of its functions, since the fact that it has something that conflicts doesn't mean it necessarily performs the function as well.
The real choice now is between the few remaining products like Spybot S&D that work well with a few stand alone AV and other protection programs or an All-in-One suite. In Spybot's case you can also individually disable or undo most of its protection, so you can simply choose to use it as an on demand scanner if you wish. This means that it can co-exist with even most suites as long as they don't falsely detect portions of it's protection as malware as AVG is doing here.
In this case I think you've made the right temporary choice, but in the long run you'll need to determine how well this combination is protecting you. If you can understand what your programs are telling you and have either avoided or at least been informed when you've experienced malware, that's a reasonable combination. If others use your PC though, you'll need to look at what they require to help them effectively, since what they do will affect you to.
Bitman
In the interest of full disclosure, I am also OneCareBear on the Microsoft Windows Live OneCare Forums, which is another complete suite product that coexists well with Spybot S&D. This proves that it can be done, which is why I support both products.
), upgrading was a definite NO (for now :laugh
. I kinda still wanted a change though (probably unnecessary) - this caused me to move to avast! 4.8. 
(luckily they have different skins)
