embellishment in 'COMPOSE' box

i have win-xp.
when i try to compose text in yahoomail, some of the buttons, such as font style, font size etc do not function. in fact all buttons were perfectly working a few months ago. then, rather suddenly, the 'TEXT COLOR' & 'BACKGROUND COLOR" buttons failed to function. over the last week or two, the other buttons that one uses in the 'COMPOSE' box of yahoomail started to fail. during the last week, even other buttons in yahoo mail INBOX, 'REPLY', 'MOVE', 'FWD' etc have started to fail to function. it is weird, in that the behaviour looks like the yahoomail is slowly dying.
this happens only while using internet explorer. in any case, other browsers like firefox, opera, netscape etc do not have any provision for embellishing the text messages in 'COMPOSE' box.
i have, several times, scanned my laptop [DELL INSPIRON] with several anti-virus tools, i have completely fresh-downloaded Internet Explorer and had them scanned too.
the problems persist.
would be grateful for help in getting back my embellishment tools.
svn
24 march '06.
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This appears to be an issue with Java and the various browsers.

Yahoo! Mail working properly shows all the same buttons in all browsers.

You might try the latest Java: http://www.java.com/en/download/index.jsp

But also check the browser settings for Java use. e.g. I.E. Tools > Internet Options > Advanced > Java

Also curious by what you mean here: "i have completely fresh-downloaded Internet Explorer "

As I.E. is an integrated part of XP I am wondering what you downloaded and if perhaps that is an issue