One question while I investigate this further:
Are you using the newer 18.104.22.168 Antivirus Engine?
The patch has been applied, the engine version is now shown as 22.214.171.124
Update on issue 2.....
There is a MS hotfix available which resolves this issue, which can occur with other AV solutions as well as LANDesk AV. It can also affect 32-bit systems, contrary to my original post (although I haven't seen this). There are also other variables, as I wasn't able to reproduce the issue on other systems of the same OS level etc.
If anyone needs details on this hotfix, please let me know.
Issue 1 still outstanding, LANDesk support investigating.....
Please post the details of the hotfix and I will create a knowledgebase article regarding this. Thank you very much for this information.