I need to upgrade my ASA 5510 running 8.0(4)28 to 8.0.5.ED to resolve an issue with IIS serving up pages correctly.
Are there any issues or bugs with this release?
8.0.5 is the latest but there should be a 8.2.x release coming out shortly. The botnet feature in 8.2 is pretty sweet. If I managed an ASA I would want it.
Yes 8.2.x is older than 8.0(5) for ASA. You can clearly see in release notes of 8.2.x that it is released on June 15th while 8.0(5) was released on Nov 2009.
Coming to your question, of which one is better or why should you go back to older code. I would say, It all depends on what features you are looking for on your ASA code, and what bugs hit your ASA in any code.
Having siad that, you can always go for the latest code, as that woudl have moft of the software defects in fixed status.