'Cannot find project or library' when run vba

I am rolling out an excel package to multiple users and have found that on just one of around 40 staff is having a problem running the VBA, specifically when it gets to the line of code including: tbTodaysDate = Format(Date, "dd mm yyyy") & " " & Format(Time....

Basically it doesn't recognise the VBA constants format, date or time (amongst many other). I've spent some time investigating this and have found that this is due to a conflict with references on different machines. The user having the problem is running the same version of windows and excel (2010) and I have check the preferences for the package on her machine and she has exactly the same. I'm assuming it's the 'Visual Basic for Applications' reference that is at fault. Lots of web sites say that that happens when the reference is ticked, but "Missing", but this isn't the case.