PB sync is broken for me

Do you remember briefly introducing PB sync in version 5.2? While it was there I uploaded four resources, and since then all four have tried and failed to sync back to my machine. I've put up with it since, but it's a real pain because the download cancels indexing, so I have to go offline every time I add a new resource or get an update (which, with freebies, is several times a week).

But it's still happening in 5.3, which suggests I might need some manual intervention at the server end. I've tried re-uploading all my PBs, checked various databases and the BITS queue, and can't see where I can fix it at my end.

Here are my logs:

2014-08-31 21:40:50.2234 6 Warn DownloadJob BITS error 0x80190193 (context: RemoteFile): HTTP status 403: The client does not have sufficient access rights to the requested server object.
2014-08-31 21:40:50.2482 6 Warn IndexerProgram The download job 'Update:9283' for update 'Resource PBB:d6f243279c19494680c5950c506d410e', downloading to 'C:\Users\Mark\AppData\Local\Logos5\Data\1lbojls4.d0n\UpdateManager\Resources\9283' has status 'Failed'; removing the job.
2014-08-31 21:40:50.3335 6 Info IndexerProgram The download job 'Update:9283' for update 'Resource PBB:d6f243279c19494680c5950c506d410e' has failed 1 time; re-queueing it.
2014-08-31 21:40:50.3701 6 Info IndexerProgram There are 0 updates downloading (out of a maximum of 4); starting a new job (from 1 queued updates).
2014-08-31 21:40:51.4314 6 Warn DownloadJob BITS error 0x80190193 (context: RemoteFile): HTTP status 403: The client does not have sufficient access rights to the requested server object.
2014-08-31 21:40:51.4752 6 Warn IndexerProgram The download job 'Update:9283' for update 'Resource PBB:d6f243279c19494680c5950c506d410e', downloading to 'C:\Users\Mark\AppData\Local\Logos5\Data\1lbojls4.d0n\UpdateManager\Resources\9283' has status 'Failed'; removing the job.
2014-08-31 21:40:51.5042 6 Info IndexerProgram The download job 'Update:9283' for update 'Resource PBB:d6f243279c19494680c5950c506d410e' has failed 2 times; re-queueing it.
2014-08-31 21:40:51.5363 6 Info IndexerProgram There are 0 updates downloading (out of a maximum of 4); starting a new job (from 1 queued updates).
2014-08-31 21:40:52.5633 6 Warn DownloadJob BITS error 0x80190193 (context: RemoteFile): HTTP status 403: The client does not have sufficient access rights to the requested server object.
2014-08-31 21:40:52.5668 6 Warn IndexerProgram The download job 'Update:9283' for update 'Resource PBB:d6f243279c19494680c5950c506d410e', downloading to 'C:\Users\Mark\AppData\Local\Logos5\Data\1lbojls4.d0n\UpdateManager\Resources\9283' has status 'Failed'; removing the job.
2014-08-31 21:40:52.6080 6 Info IndexerProgram The download job 'Update:9283' for update 'Resource PBB:d6f243279c19494680c5950c506d410e' has failed 3 times; re-queueing it.
2014-08-31 21:40:52.6310 6 Info IndexerProgram There are 0 updates downloading (out of a maximum of 4); starting a new job (from 1 queued updates).
2014-08-31 21:40:53.6934 6 Warn DownloadJob BITS error 0x80190193 (context: RemoteFile): HTTP status 403: The client does not have sufficient access rights to the requested server object.
2014-08-31 21:40:53.6989 6 Warn IndexerProgram The download job 'Update:9283' for update 'Resource PBB:d6f243279c19494680c5950c506d410e', downloading to 'C:\Users\Mark\AppData\Local\Logos5\Data\1lbojls4.d0n\UpdateManager\Resources\9283' has status 'Failed'; removing the job.
2014-08-31 21:40:53.7139 6 Error IndexerProgram The download job 'Update:9283' for update 'Resource PBB:d6f243279c19494680c5950c506d410e' has failed 4 times; aborting it.

And here's the error message from the server.

HTTP/1.1 403 Forbidden
Content-Type: application/xml
Connection: keep-alive
Date: Sun, 31 Aug 2014 23:06:15 GMT
Server: AmazonS3
X-Cache: Error from cloudfront
Via: 1.1 561085d53a4e48ca1d4addc0d3176c57.cloudfront.net (CloudFront)
X-Amz-Cf-Id: CUgRhf7ML3DP4GO1oXyVf1fACEZgzyzOGaew0bUL6eF-qJ57lJsJNg==