LMS 7.8 - latest nightly build - stalling on G drive scanning for new/changed files

Since yesterday, 7.8 on Windows 7 64-bit, has been stalling after it scans for new and changed files on 1 of 3 USB drives on my system that is a dedicated SB server.

All 3 drives are configured in SB to be scanned.

A clear library and rescan works fine.

The server log has no entries except:

[12-09-16 09:40:52.4467] Slim::Utils::Scanner::Local::rescan (171) Discovering audio files in G:
[12-09-16 09:44:26.8881] Slim::Utils::Scanner::Local::__ANON__ (254) Removing deleted audio files (0)
[12-09-16 09:44:26.8883] Slim::Utils::Scanner::Local::__ANON__ (332) Scanning new audio files (4)
[12-09-16 09:44:26.8889] Slim::Utils::Scanner::Local::__ANON__ (410) Rescanning changed audio files (0)

SB server indicates:

Discovering files/directories: G: (64802 of 64802) Complete 00:01:21
Scanning new music files: G: (4 of 4) Complete 00:00:03

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Any ideas?