Installer crash - cannot readglobal/config_exec_params

I've had a weird crash in the installer a few times now over the last
two or three weeks, though it seems to be somewhat unpredictable. I
can't quite figure it out, hence this post.

It occurs towards the end of the installation, I think when the PLs are
being installed (pretty sure it's not the contribs as I saw it once or
twice before they were added) which happens immediately after the
service has started. Basically a windows error pops up saying
postgres.exe closed unexpectedly because of an error. The installation
continues regardless, and leaves me with what appears to be a completed
installation and running server. All the PLs are there as appear to be
the contrib modules.

This time though, I noticed an odd error in the server log, right at the
beginning:

FATAL: could not read from file "global/config_exec_params": Permission
denied
2004-09-10 16:43:07 GMT Daylight Time LOG: server process (PID 1376)
was terminated by signal 5
2004-09-10 16:43:07 GMT Daylight Time LOG: terminating any other active
server processes
2004-09-10 16:43:07 GMT Daylight Time LOG: all server processes
terminated; reinitializing
2004-09-10 16:43:07 GMT Daylight Time LOG: database system was shutdown
at 2004-09-10 16:42:53 GMT Daylight Time
2004-09-10 16:43:08 GMT Daylight Time LOG: checkpoint record is at
0/AB4950
2004-09-10 16:43:08 GMT Daylight Time LOG: redo record is at 0/AB4950;
undo record is at 0/0; shutdown TRUE
2004-09-10 16:43:08 GMT Daylight Time LOG: next transaction ID: 494;
next OID: 17228
2004-09-10 16:43:08 GMT Daylight Time LOG: database system is ready

Regards, Dave