File Output Pluging creates corrupted files

Hi everyone,
we are using the file output plugin with gzip=true and we are getting quite a bit of corrupted files. At first we thought that it had to do with the size of the files but it appears quite randomly. Some of our files are +2GB when compressed. I looked into the file output plugin code and noticed that when new files are crated they are actually opened with, "a+") line 262 and 264 and I am now wondering if this should be, "ab+")

in the case of gzip files being binary. I am unfortunately not familiar with jRuby and am not sure if this creates the problem. Any help is highly appreciated.