That file was one that you had / have to get from LANDesk, I am not sure if they are still suggesting its use.
Have you installed any of the post SP3 patches and if so, did you update your clients to match?
here you can find some hints about the cause and tip how to solve it:
I think it is not so easy to create a common script for it which could kick a specific LANDesk task on a client by LANDesk, if locked by LANDesk SWD task...
I think it could be possible with the Console Extender where you can embed scripts and tools with parameters which can do such stuff on a client... but you need the rights to connect to admin shares on the clients directly to run something on admin$ or c$ on the client :-)
I ended up using a generic managed script with the following.
REMEXEC0=cmd /c taskkill /F /IM sdclient.exe
REMEXEC1=cmd /c rmdir /s /q "C:\Program Files\LANDesk\LDClient\sdmcache\packages"
REMEXEC2=cmd /c rmdir /s /q "C:\Program Files (x86)\LANdesk\LDClient\sdmcache\packages"
Seems to do what I need it to. I kills the sdclient.exe process and removes the existing packages so both processes will start fresh.