Vista - Problem reconnecting offline files when mapped as a drive

I have vista business, sp1. I use offline file a lot, and it works well most
of the time. But I have found that when the folder is set as a drive
mapping, and made to be offline, that often it does not re-connect when the
server is available. When I try to go to the server, all I see is the files
that are stored offline, and not all of the files available on the server (I
have only made some folders available). If I remove the drive mapping, then
it will reconnect. Also, without un-mapping the drive, if I put in the ip
address of the server in the form \\1.2.3.4 then I can log on, and see the
folders, so I know that the server is available. Does anyone have
suggestion, other than to not map the server. I like mapping the server,
because it makes the folders easily accesable in explorer.