I've run into this error (and similar ones) often enough while browsing the web.
"The instruction at '0x10005f6c' referenced memory at '0x10005f6c'. "The memory could not be read".
Based on my experience, this is almost always a badly written BHO (Browser Helper Object). My current client has been fighting this error with a yellow pages application provided by SWBell. As long as you had another browser window open when you closed their web-based app, you didn't get the error. But if their app was the only browser window open you'd get that annoying message when IE closed. We figured out that we could eliminate the error by disabling that BHO (Tools-Manage Add-Ons) but I'm not sure about hte negative consquences of doing that. In the case of Adobe, their DLL (AcroIEHelper.dll) was dated 12/14/2004 with my "old" version of Adobe-7.0.3. It is pretty obvious that they hadn't updated that DLL in a while. Fortunately, 7.0.7 updated that DLL and the memory error is now gone.
I run into this error all the time with Flash sites as well..I guess Macromedia needs to learn something from Adobe and get their DLLs updated as well.
Also, it appears that the memory address given in the error is consistent depending on what BHO causes the problem. I don't have any of the others documented but I'll try to add them to this doc as I run into them.
In addition, it doesn't seem to matter whether you use IE or Firefox--I've run into the exact same errors in both browsers..