Working Copy not compatible with TortoiseSVN

It can be useful to occasionally work on the raw files outside of Visual
Studio (eg when working around the missing renaming functionality or even
just checking on file status). I like to use TortoiseSVN to do this.
If I create my Working Copy using "Open from Source Control" then for some
reason, my Working Copy seems incompatible with TortoiseSVN. The highest
level of files have the correct status and are marked as being source
controlled, but any subfolders and their contents are not marked as being
source controlled (even though they are). This makes it difficult or
impossibly to work with TortoiseSVN on these files. I seem to be able to
perform operations on individual files, but I cannot work on any folders or
trees of files. If I try, I get errors like: "Working copy
'C:\svnroot\blah...' not locked".
If I delete this working copy and then checkout the root module using
TortoiseSVN, then all files, folders and subfolders appear to be source
controlled and I can freely work with TortoiseSVN with no errors.
So it appears that there is different svn information generated when
checking out from TortoiseSVN as opposed to checking out using Visual
Studio .NET. Is this due to the way that Visual Studio does its checkouts?
(I noticed that Visual Studio seems to "walk" the directory tree, checking
out each folder and subfolder individually).