In task manager, does the TWS process (javaw.exe) have a *32 next to it? That's how you can tell if a process is running as 32 bit or 64 bit.
The easiest solution is to update the shortcut. Click properties and change the target to the following. C:\Windows\SysWOW64\javaw.exe -cp jts.jar;pluginsupport.jar;hsqldb.jar;jcommon-1.0.12.jar;jfreechart-1.0.9.jar;jhall.jar;other.jar;riskfeed.jar;rss.jar -Dsun.java2d.noddraw=true -Xmx512M jclient/LoginFrame C:\Jts