gTasks fails to connect to my Google/Gmail account.

1. Before going dipper, and to save your time, you should double check that you entered your email and password correctly.
2. If you turned on 2-step verification on your Google account, you should create an application specific password in your Google account settings, as described here.
3. Google may locked your account for Captcha.
   To unlock Captcha for Gmail or personal Google account, follow the link: https://www.google.com/accounts/UnlockCaptcha
   
   To unlock Captcha for Google Apps account, check the following URL and replace ‘yourdomain’ with your Google Apps domain name: https://www.google.com/a/yourdomain.com/UnlockCaptcha
4. If you are using Google Apps account, gTasks is designed to work with Google Apps new infrastructure.
   New and recent Google Apps accounts are already set with the new infrastructure.
   Older Google Apps accounts are transitioning to the new infrastructure.
   You can choose to transition your Google Apps accounts to the new infrastructure on your own timeline until the date of your automatic transition.
   You can read more info here about Google Apps transition to the new infrastructure.

Due date’s time and alerts are not synced across my devices.

Since Google Tasks doesn’t support due date’s time and alerts, these are kept locally on your device and not synced to Google Tasks.
This is the reason that time and alerts are not synced across your devices.
I am working on a work around for this issue…

Date picker shows time only, doesn’t allow to select a date.

Restart your device by turning it off (press and hold the sleep/wake button, then slide the appearing red slider), and back on (press the sleep/wake button).

Alerts or app badge is not working on iOS 5.

You should make sure that notifications are enabled for gTasks app.
Go to your iPhone/iPad settings, tap the “Notifications” item, and locate gTasks in the app list.
Tap gTasks and make sure that “Notification Center” is on, “Alert Style” is either “Banner” or “Alerts” and “Badge App Icon”, “Sounds” and “View in Lock Screen” are on.

I purchased gTasks before, restored my iPhone and had to reinstall gTasks.
How do I restore my purchase?

To restore your purchase you should tap the “I already purchased” button in the purchase screen of gTasks.

When I touch the date picker to set a due date or an alert, the date picker slides back down.

This issue happens on jail-broken devices that installed the “Action Menu” tweak.

It seems that the “Action Menu”, which is an unauthorized app, tweaks some internal iOS components that results in this issue. Other Apple-authorized apps may suffer from this issue as well.

I am trying to find a work-around for this issue. Meanwhile, the best solution would be to uninstall or temporarily disable “Action Menu”.
If you like to keep “Action Menu” active, you can disable only the “Extended Support” in its settings. This will also resolve that issue.

I swipe a task horizontally but an unexpected behavior occurs.

Different behavior for task swipe is set for different tasks order setting.

If the list’s tasks order is manual, then the sub-tasking option is available, and tasks swipe will result in sub-tasking operations.

If the list’s tasks order is anything other than manual, sub-tasking is not possible, and tasks swipe will result in appeared task delete button.