RODBC looks at the default folder for the ODBC server connection to see if you have write permissions there (even if you are going for a subdirectory). If you don't have master permissions, then it fails.
I had to create two connections within R, one for reading from the master and one for writing to my temp directory.
These were set by creating two server connections using my local computer's ODBC Administration (within Win7):
-One that defaults to the write-protected master server directory and that I use to pull read-only data.
-One that defaults to the server directory that I have write/drop permissions to.
In other words, your problem is solved by changing your machine's ODBC connection and having R point to the new server connection you will make (the one that defaults to your write-permissioned table.