I'm using two test PCs.
One is mine, and I don't reboot it often. It is, however, the PC I used to examine the useOptions effects, and I rebooted it about 10/15 times during the tests, always without problems.
The other is a colleague's PC, and she reboots it daily. She's also doing fine since the REG DELETE trick.
Are you using persistent drives? If so, are you sure that you are running REG DELETE after Windows has automatically reconnected them? If you allow "fast logons" (i.e. logons using cached credentials, with the network being setup after logon), could it be that you run REG DELETE too early?
I disabled them, to stay on the safe side, and unfortunately I hadn't time enough to test with and without "fast logons" enabled.