Same problem for me.
Running WP 3.4, Social 2.6 and Twitter Tools 3.03. All of this on top of WAMPServer 2.1.
Manually downloading tweets works fine. Scheduled download never works.
WP-Cron jobs are set up. Social is configured to run every 15 minutes.
I’ve run some debugs on both Twitter Tools and Social, and see this in the event log if I try and run the Social cron job manually:
{SOCIAL – 2012-11-01 15:44:56 – 10.1.200.7] Running cron_15_init
[SOCIAL – 2012-11-01 15:44:56 – 10.1.200.7] Running request: CRON/action_cron_15
[SOCIAL – 2012-11-01 15:44:56 – 10.1.200.7] Attempting semaphore lock
[SOCIAL – 2012-11-01 15:44:56 – 10.1.200.7] Semaphore lock failed. (Line 40)
I suspect this is the cause of the problem. Now I just need to work out how to fix it ??