When you Save Configuration from the Server menu drop down list, you receive:
An error occurred while backing up the configuration. The filename, directory name, or volume label syntax is incorrect.
To save the configuration of a remote computer, SP6 requires that the target drive and folder must exist on both the local and remote computer.
If you can't, your only solution is to revert to SP5, SP4, or SP3.
If you do uninstall SP6, don't forget to apply the hotfixes appropriate to your new Service Pack.