Not all keywords in report

Hey everybody,
I check every day round about 275 keywords for their SERP ranking in google.com - some keywords show no ranking in the report. But when I check them manually with the "quick ranking check" then I get an result.
The Log Manager doesn't show any errors. Can somebody reproduce this issue - or can someby give me a hint how to solve it?
Thanks
Markus
I check every day round about 275 keywords for their SERP ranking in google.com - some keywords show no ranking in the report. But when I check them manually with the "quick ranking check" then I get an result.
The Log Manager doesn't show any errors. Can somebody reproduce this issue - or can someby give me a hint how to solve it?
Thanks
Markus