The most reliable Java is from filehippo.com.
I've heard a number of complaints about SunJava's download sites.
Though I believe it's the best Java, where you get it makes a diff.
At least this is what I've heard about SunJava to date.
Check your 'program files' file and see if there is any problems like ? or !.
Delete them. Uninstall java and reinstall from filehippo.com.
Personally I loaded NetBeans also, just for fun.
There is also Java development tools there, as you probably already know.