● Might try deleting that gmail account APP Cache, shut down, restart and check it (in manage APPs).
● Next u could delete the gmail cache & Data, shut down , restart & check again.
● If that does not work delete the gmail account from your tab, shut down, re-start & add the gmail acct again..
● Last, if none of the above have worked, do a system reset, but be sure to back your stuff up to SD Card or computer.
If you have a lot of APPs, use free App List Back up on market & email the list to yourself so you know what you have, u should have your tab account set up in Google acct to back up APPs anyways (so after reset they can be re-downloaded easier), but I suggest both.