Signal Light Out, Bulb Replacement Doesn't Fix

Hey Guys,
I have done a search but didn't find anything that seemed to relate to my issue except possibly the thread about the guy that kept blowing turn signals.
My left rear turn signal blew a month ago and I replaced it with no issues. It has now blown again 3 weeks later and when I replace the bulb with a new one it does not work. It acts as though the bulb is still blown, the front signal flashes quickly. The bulb I removed looks fine, the filament seems to still be intact. I don't believe this to be fuse related as I don't think either signal would flash if the fuse was blown.
Does anyone know where I could start to diagnose this issue, as it has me stumped?

Thanks

BTW this is a 2001 Sunfire SLX

Could be the the thing the bulb plugs in. i had a grand am replaced the bulb and the new didnt work either. went to a junk yard got a new thing the bulb goes in, you know what im talking about, and replaced it and that was it.

Thats a good thought the socket might be messed up. Maybe stressed the wires taking it out to replace the bulb last time. I'll break out the multimeter and check the wires. Anyone else have thoughts?

yeah the socket couldnt think of what it was called. ok let me know how it goes.