If you make a new "Local Server" in gateway with the following settings, you should be fine.
The simplest way to do this is to click the link in the news box up there. *points skyward* For right now the one click link will not work, please set up a manual connection as explained here.Remember to reset your patches if you don't get the new sylvan heart login screen.
New IP as of 7/02/2010 (July 2nd, 2010) * IP : jhs59.homeip.net
* Port: 1980
* Patches :-
o
http://www.sylvandreams.co.uk/sd/vmtdbdfh.rar o
http://www.sylvandreams.co.uk/sd/client.rar o
http://www.sylvandreams.co.uk/sd/uose-statics.rar o
http://www.sylvandreams.co.uk/sd/cliloc2.rarScreenshot of the settings page :-

One user has also mentioned that they had problems setting it up this way, and that downloading the rar files and using the "add file" option in gateway sorted it for them, so as a last resort you could try that :-)
If you're using Windows XP and your client crashes immediately after startup, here are some instructions contributed by Damira
-Go to the sylvan heart settings in UO Gateway.
-Note the "directory" address there. This is where your client is located.
-Go to that client, right click, select properties.
-Go to "comptatibility", click the "run the program in compatibility mode for", and select Win98.
-Go back to gateway and lauch Sylvan Heart. No need to reset your patches.