Thanks for the translation and testing.
In my quest to check all possible messages (testing error messages is quite tricky, as we really don't know how to "trigger" them all), I found the following error dialog:
The message appears when there is an error on sending a request. The two undefiend should be a error status and error message such as "404" and "Not Found". In your test, it could not get the error information since it was conducted offline. Anyway, the information is shown only for debugging. It is not a bug.
Apart from that, I seem to see the string "Send request" in Thunderbird's status bar when Google Contacts are reloaded.
It is a message for debugging. I forgot to remove it. You do not need to translate it.
Finally, a question about "wording":
In file: gmcont_settings.dtd
Confirm entries to be deleted before synchronizing reserved changes
-->What does "reserved" refer to?
Sorry for my poor English
Google Contacts have two sync modes: Interactive and Batch. In the interactive mode, changes of a card are submitted to Gmail immediately. On the other hand, the batch mode, changes are not submitted immediately and send to Gmail when you click the Reload button. The "reserved" means the unsubmitted changes. Google Contacts show an alert if the "reserved" changes include deletions of cards(contacts) and the option enabled.
If you have a better string, please let me know.