Plz tell me if its a yahoo problem that when i type in a chat box with my fiance that we dont always get the replys that are sent is this a yahoo problem

Not a yahoo problem, but a scripting problem, either your IE settings are incorrect or the Messenger support software is the problem
You may have scripting disabled in your Internet Explorer.
To enable scripting: Click "Tools"
Click "Internet Options."
Click "Security" tab.
Click "Custom Level" button.
Scroll down to "Script ActiveX.controls marked safe for scripting"- enable
Scroll down to "Scripting - Active scripting" - enable
Scroll down to "Scripting of Java applets" - enable
Click OK
Click OK

Still not working ? Update software

use the links on this page to help update software.

http://help.yahoo.com/l/us/yahoo/messenger/messenger9/notices/mstabuguqscripterror.html After updating check you do not have old versions of Flashplayer, Shockwaveplayer and Java running alongside the latest - this can cause conflicts
Start / control panel / programs
delete any old versions

It has to do with your connection and make sure your system is virus free