Last week, we have upgraded to solidworks 2009 SP5.0. I have come across this bug in the program yesterday. I have shown this to our VAR as well and they are looking into it. I am still posting it here to see if other people can also reproduce the problem.
To check this, you need to be using pdm work group and you need "Property Mappings..." done in the vault admin. I have a proerty mapping with different title in the "SolidWorks Work Group PDM Property" and "SolidWorks Property". (What I mean is that my PDM property is "Manufacturer's Name" while the same property displayed as "Vendor Name" in SolidWorks file). This is little complicated but I am sure people are using property mappings.
My problem is that when I open a solidworks part file and delete "Vendor Name" property and then when I check in that part, property still shows in the check in dialog box and it gets added to the part after check in. Once property is deleted from solidworks file, it should not appear in the check in dialog box at all. It worked fine all these years in solidworks 2007.
Thanks in advance,