Lg Vortex lock screen signs me out of google talk

[berttany19]

I'm new to the droid and I have the lg vortex. I notice that after so long my screen goes off and it locks. I like that it locks so I dont pocket dial, so that is something that I do need. But it also signs me out of google talk in the process. Does anyone know how to fix this problem? Just because my phone locks it shouldn't sign me out of a messenger client, or am I wrong? No other phone that I've had has done this. If you have any ideas, I would appreciate it. Thank you!