BrowsableAttributeAttribute and DesignerSerializationVisibilityAttributeAttribute do not exist in namespace 'System.ComponentModel'

i've inherited control runs fine in original solution on pc has ever had silverlight 3 installed. when compile own new solution errors on 2 attributes browsableattribute , designerserializationvisiblityattribute compile-time error complaining not exist in system.componentmodel

a search on either attribute using latest sdk chm file shows nothing these attributes. similar search on these forums returns bunch of posts complaining how bad search facility here is!

and yet have solution file happily compiles using these attributes.

can point me can find information on these attributes in silverlight documentation (and dlls required - msdn tells me system.componentmodel in system.dll) , or give me clue why might compiling fine in 1 project , not in another?

two of have eye-balled different references (between solution resolves references , 1 doesn't) , can see no differences - both pointing @ version 2.0.50727 dlls in framework\silverlight\v3.0 folder or sdks\silverlight\v3.0\libraries\client folder

very frustrating!

edited add visual studio's object browser show browsableattribute being in system.component

i use resharper works out assemblies load me. saves time wants remember located?

i added browsableattribute , added reference:

c:\program files\microsoft sdks\silverlight\v3.0\libraries\client\system.componentmodel.dataannotations.dll

both attributes compatibility wpf, aren't used silverlight @ remove them if control isn't sharing code wpf project.

Silverlight  >  Silverlight Controls and Silverlight Toolkit