Single User Mode fails in SQL Server 2000 with ERRORLOG sharing er

I'm trying to restart SQL Server 2000 in single user mode from the command
line and receive this error:

C:\Program Files\Microsoft SQL Server\MSSQL\Binn>sqlservr.exe -c -m

2006-11-29 09:58:59.78 server    initerrlog: Could not open error log file
'E:\P
rogram Files\Microsoft SQL  Server\MSSQL\log\ERR
ORLOG'. Operating system
error = 32(The process cannot access the file because it is being used by
another proces
s.).

I ran filemon on the ERRORLOG file and tried again.  I saw that the process
sqlservr.exe:2160 shows WRITE SUCCESS and then I try the single user mode
command and see sqlservr.exe:5036 OPEN SHARING VIOLATION.

So, does anyone know what's going on?

By the way, this is a clustered instance and the ERRORLOG is on a LUN on the
SAN, if that makes any difference.  I'm trying to manually restart SQL Serve
r
in single user mode to troubleshoot a system database restore issue from a
3rd party backup software.

Thanks,

David