troubleshooting backup error, what's wrong?

Fairly new to Acronis and still working out the kinks. I have 2 nightly backup jobs that run - one to an internal hard drive, and another job that backs up to a portable USB drive. Last night the 2nd backup job failed for some reason and the reason is not apparent to me.

I run a pre-job command that does a CHKDSK on the drive, and it almost seems like Acronis somehow failed because of this batch file - even though it appears to have executed fine. Can anyone confirm?

Here is the log:

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Log Entry Details
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Type: Error
Date and time: 2/5/2014 2:00:10 AM
Backup plan: Nightly Backup External
Task: Full backup
Code: 20,250,685(0x135003D)
Module: 309
Owner: administrator@domain
Message:
Command 'Running backup plan 'Nightly Backup External'' has failed.
Additional info:
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Error code: 61
Module: 309
LineInfo: 4a8728dc8a1c950f
Fields: $module : mms_vs_38350
Message: Command 'Running backup plan 'Nightly Backup External'' has failed.
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Error code: 41
Module: 307
LineInfo: e6792a5ee190dda6
Fields: $module : agent_protection_addon_vs_38350
Message: Failed to execute the command.
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Error code: 1024
Module: 0
LineInfo: 858cc05f488a8dcc
Fields: ExitCode : 1, $module : mms_vs_38350
Message: Child process has exited with code '1'.
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Error code: 3
Module: 167
LineInfo: 6bf76712d83410c4
Fields: $module : mms_vs_38350
Message: Failed to execute command '
C:\Windows\system32>chkdsk g: /f
The type of the file system is NTFS.
Volume label is EXTERNAL_TUESDAY.

Stage 1: Examining basic file system structure ...
Progress: 0 of 64 done; Stage: 0%; Total: 2%; ETA: 0:00:02
Progress: 64 of 64 done; Stage: 100%; Total: 5%; ETA: 0:00:02 .

64 file records processed.

File verification completed.
Progress: 0 of 0 done; Stage: 99%; Total: 14%; ETA: 0:00:02 ..

0 large file records processed.

Progress: 0 of 0 done; Stage: 99%; Total: 14%; ETA: 0:00:02 ...

0 bad file records processed.

Stage 2: Examining file name linkage ...
Progress: 90 of 90 done; Stage: 100%; Total: 28%; ETA: 0:00:01

90 index entries processed.

Index verification completed.
Progress: 0 of 0 done; Stage: 99%; Total: 28%; ETA: 0:00:01 .

0 unindexed files scanned.

Progress: 0 of 0 done; Stage: 99%; Total: 28%; ETA: 0:00:01 ..

0 unindexed files recovered.

Stage 3: Examining security descriptors ...
Security descriptor verification completed.
Progress: 0 of 0 done; Stage: 100%; Total: 99%; ETA: 0:00:00 ...

14 data files processed.

CHKDSK is verifying Usn Journal...
Usn Journal verification completed.

Windows has made corrections to the file system.
No further action is required.

976728063 KB total disk space.
394865984 KB in 23 files.
256 KB in 15 indexes.
0 KB in bad sectors.
68287 KB in use by the system.
65536 KB occupied by the log file.
581793536 KB available on disk.

65536 bytes in each allocation unit.
15261375 total allocation units on disk.
9090524 allocation units available on disk.
'.
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Acronis Knowledge Base: http://kb.acronis.com/errorcode/

Event code: 0x0135003D+0x01330029+0x00000400+0x00A70003

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