VSS_E_WRITER_INFRASTRUCTURE is a possible indication that the Windows 2003 Volume Shadow Copy Service is not running or is an error state. A -1 return code from applications typically means that they didn't even have enough infrastructure present to get started. We don't have context on your problem, as in whether this is a new client deployment, or an older client with an unchanged configuration whose backups worked before; or what you've investigated (TSM error log, Windows Event Log, VSS state, etc.).
Richard Sims
