1.8 commit failed - nothing in the error logs

I just had a commit fail midway on three different 1.8 clients without any kind of error logged in the output, in the client's Event Viewer (Win7,) or on the repo server's httpd logs (linux.) No dump file either. Starting with a fresh checkout made no difference. There's no pre-commit hook. I have used 1.8 to do merges and commits previously.

The commit did work with a 1.7.9 client (collabnet on win7 in a fresh workspace.)

1. Does anyone have any more ideas on where I can check for additional error logging? (on Win7, Cygwin clients, and Apache on a linux repo server.)
2. Has anyone seen this behavior before in 1.8? My google-fu found nothing.

This was with three clients, "svn, version 1.8.0 (r1490375)" for all three: Cygwin svn client, TortoiseSVN, and CollabNet's client in a CMD window. Server is at 1.6.18 (r1303927) (CollabNet) over https.

I was adding a vendor branch manually:
1. svn copy ^/branches/build-pipeline-plugin-3.3 build-pipeline-plugin-1.3.4.1
2. cd build-pipeline-plugin-1.3.4.1
3. rm -rf; rm -rf .* (OS delete)
4. Extract the build-pipeline-plugin-1.3.4.1.tar.gz into the now empty dir
5. svn status | grep '^?' | sed 's/^?//' | xargs svn add (To add any new files.)
6. svn status | grep '^!' | sed 's/^!//' | xargs svn rm (To delete any removed files.)
7. svn ci -m 'Added 1.3.4.1 from https://github.com/jenkinsci/build-pipeline-plugin/releases/build-pipeline-plugin-1.3.4.1' (or use TortoiseSVN's "SVN Commit")

After each failed commit, 'svn cleanup' was required since everything was still locked.

On both the cygwin client and collabnet windows client, the check-in just stopped midway at the same point without any message. The exit code was set to 1 however.
        $ svn ci -m 'Added 1.3.4.1 from https://github.com/jenkinsci/build-pipeline-plugin/releases/build-pipeline-plugin-1.3.4.1'
        Adding .
        Deleting .hgignore
        Deleting .hgtags
        Deleting .pmd
        Adding README.md
        Sending pom.xml
        Sending src/main/groovy/au/com/centrumsystems/hudson/plugin/buildpipeline/BuildJSONBuilder.groovy
        Sending src/main/groovy/au/com/centrumsystems/hudson/plugin/buildpipeline/ProjectJSONBuilder.groovy
        Sending src/main/java/au/com/centrumsystems/hudson/plugin/buildpipeline/BuildForm.java
        Adding src/main/java/au/com/centrumsystems/hudson/plugin/buildpipeline/BuildGrid.java

        $

The TortoiseSVN client did create an error report, but I think it just means that TortoiseSVN is blocked (firewalled) from connecting to its error reporting server. Plus the 1.7 client commit worked, and I have used the cygwin 1.8 client to do merges and commits previously, so it "can't" be a permissions issue.
        ---------------------------
        SendRpt: Error
        ---------------------------
        Error 403 fault: SOAP-ENV:Server[no subcode]
        "HTTP/1.1 403 Forbidden"
        Detail: HTTP/1.1 403 Forbidden
                
        Content-Type: text/html
        Server: Zscaler/4.1
        Cache-Control: no-cache
        Content-length: 3649
        
        HTTP/1.1 403 Forbidden
        Content-Type: text/html
        Server: Zscaler/4.1
        Cache-Control: no-cache
        Content-length: 3649
        
        HTTP/1.1 403 Forbidden
        Content-Type: text/html
        Server: Zscaler/4.1
        Cache-Control: no-cache
        Content-length: 3649
        
        ... snip ...
Received on 2013-07-08 18:20:16 CEST