Hi Kevin,
i had these problem when using the wireless client card supplicant software and switched between the software and windows configuration.
I deinstalled the supplicant and used only the Windows settings.
What also helped was the other way: Deleted the Windows settings. Deinstalled the supplicant. Installed the supplicant again.
You may have also a look on the following settings: In the SP Webpage check "Security -> Advanced Security -> Timers". Set all settings to disable.
To your Vlan doubts: Do you have a WDS configured? If yes you have to setup groups in the "Wireless Services -> WDS -> Group Settings" page.
But there are som many problems left. it would be helpful to have your config and basic network design here.
Best regards,
Frank