We're still trying to resolve the problems with OpenSRS-SF V1.58 (it won't register new domains since the September update on the server side). I honestly don't want to upgrade, since I've made lots of enhancements to the code and it works well for us (nearly all of the enhancements were done via hooks, but still...)
Can somebody who understands the API better than me take a look at this XML and see if anything jumps out at you? This has been sanitized, but the "character" of the data has not been changed, so anything data-specific should still be in there. (This is the output from the DEBUG setting in the client code).
I did a quick test, and your problem appears to be this:
<item key="f_lock_domain">no</item>
From our API documentation: f_lock_domain (int)
"no" is not an (int) :). If you do not want to lock the domain, this should either not be included, or should be null, i.e.:
<item key="f_lock_domain"></item>
There may be other problems, but this is definitely an issue.