Application-defined or object-defined error

[abdn]

Hi Folks

I have a user who uses a small excel file with a frontend, everytime the user opens the file they get " can not start. Error: Application-defined or object-defined error"
we have 4 users using the sheet and only one gets this message.
i've tried reinstalling office 2000, updated all services packs and xp service packs.
and .net and java etc.
i've checked macro security as well.The front end does open to a point if i click around i can make out the cells but thats all.
Any help would be greatly appriciated.