Negative keyword id returned from adwords api build

[P Perl]

Hello, I am currently using the AdWords API through an AdWords script and am going through a bizarre situation. I am using the

var builder = adgroup.newKeywordBuilder().withText(searchTerm).build();

Where adgroup is a valid Adgroup object and searchTerm just a valid string. Whenever I run this code, the keyword does not seem to be created, I could not find it through the UI and so I looked into it.

By using the code below I do not get any errors, and the problem is that the keyword Id returned is negative for example '-217' or '-1162.0' or ' -1.0'.

Logger.log(builder.isSuccessful()); //true

var results = builder.getResult();

Logger.log(results.getId()); //obsure negative id

Has anyone encountered this problem before? Thank you very much