Hi, I'm Molly's replacement while she's gone...
Interesting question -- I can't reproduce this behavior, and I'm also running IE on XP. I've tried setting my screen resolution to anywhere from 800x600 to 1400x1050, and I've also tried switching the Text Size parameter on my IE from medium to smallest to largest. Nothing would crop my message options menu.
Can you give us any more system information that might be useful (such as your screen size and text size setting), or anything else that you think may be relevant? In turn, I will have this question raised when we talk to Lithium (the discussion forums software provider) next time in hopes that they've seen this before and know how to fix it.
Oh, and just for reference, the options you seem to be missing are "E-Mail This Message to a Friend" and "Report to Moderator". Not that this info helps you much... 😞
Thanks,
Boris
(Molly's apprentice)