Many users of AvantGo report having problems syncing to the MAL. There are several error conditions which can result, but the most notorius is an Error 5463. Basically I understand that this is a problem logging into their MAL server. This could be due to modem, server unavailable, net traffic problems or to a conflict in login or password between their server and your software setup. Assuming your internet surfing is behaving normally and having checked your login info, you might want to check a part of the setup that their wizzard may have misconfigured and/or is misleading in the manual setup. If you are using a dialup connection, their wizzard may not configure your proxy settings since you don't use them. At the same time you might resonably think these don't need to be configured if you go through the settings manually. Wrong! It turns out they use these settings to connect to their server. To correct the problem, go to the start menu on your desktop, select programs >AvantGo >Mogile Link; click on Configure Proxy on the right side. Verify you are on the "Proxy Settings" window at the top of the screen. Check (select) the http proxy server box (top), then check the http authentication box. Fill out the proxy server name as "avantgo.com", your login name and password to whatever you use to access your desktop. Note: this is not your Avantgo login info. Click ok and try syncing again.

Hope this helps