[TYPO3-asia] Problem with running scheduler task - TYPO3 4.4.0

[Radovan Hlavaty]

Hello,

Issue: I have a scheduler task, which generates and sends newsletters, however it suddenly stopped working. In the BE I can see the Last time when the task was run and also the next time. Scheduler seems to be running the task, but when the execution comes it doesn't call the execute method in the task (i've found it out by adding a log at the very beginning of execute() method).
What's really surprising is that if i run the scheduler task manually, everything works as intended.

Task is scheduled to run every 10 minutes, and after some initialization and fetching data from database it checks, if there is a newsletter prepared for sending. If not, it just returns true. Normally I'd expect, that if the task is run it goes through the initialization part and fetches the data. I put the log even before this part, which I would expect to log every 10 minutes that the task was started, however it doesn't - which is weird. 

Has anyone come across this problem? Do you have any idea how to solve it?

I'd really appreciate if anyone encountered and solved similar issue.

Thanks in advance.
Radovan