The following can be useful for other members with difficulties concerning the wallet update.
Made by the ultracoin dev, so just replace all 'ultracoin' into 'guldencoin':

HOW TO UPDATE THE WALLET:

Step 1 : Type %appdata% in the windows search box (you see it when you click the start button)

Step 2 : Find the ultracoin folder

Step 3 : Copy the wallet.dat into a backup folder, do NOT delete or cut it!

Step 4 : Delete everything in the appdata/ultracoin, but DO NOT DELETE THE WALLET.DAT

Step 5 : Download this file http://speedy.sh/YUcJb/Ultracoin-release-1.0.2-qt.rar

Step 6 : Extract the folder from the download somewhere,now drag the Ultracoin-qt.exe from the new download into your normal wallet folder (not into the  
            appdata/ultracoin folder but your wallet folder)

Step 7 : Click yes when it asks do you want to replace the file.

Step 8 : Start the wallet,it will now download the entire blockchain again (this will take some time).