Sprobuj wyczyscic pamiec podreczna w sekcji APLIKACJE.
Ewentualnie mozesz sprobowac zrobic wipea calego telefonu czyli przywrocic do ustawien fabrycznych.

See below for the fix to the Android Os Market problem:

Go to your mobile phone settings:-

Settings -> Applications -> Manage Applications --> press menu and select "filter" then "All" -> scroll down to:-

"Checkin Service" then select "clear data"
"Download Manager" then select "clear data"
"Google Apps" then "clear data"
"Google Talk Service" then select "clear data"
"Market" then select "clear cache"

Go to your desktop computer/laptop and log into googlemail on line. When the googlemail home page displays click the link to change your email address from *@googlemail.com to *@gmail.com.

Then return to your mobile phone to reset your googlemail account
Click/touch on Settings -> Applications -> Manage Applications.
Scroll down to and Click on Google Apps.
Click on the button labelled “Clear data”
When prompted with “All information you’ve saved in this application will be deleted permanently”, click on OK
Click/touch on Settings -> Online Service Accounts -> Click Google -> setup gmail account e.g. [link widoczny dla zalogowanych Użytkowników] or open the Android Market and attempt to install an application -> you should now be prompted for your new credentials which should fix the problem.