As we all have noticed this site has a tendency to turn words like lol or hi into emoticons.
Unfortunately, I haven't been able to find a way to disable it - though still looking. However, there is a way for you to disable it manually.
To disable smiley images:
1) Click the Profile button (found in the top menu bar of the forum).
2) From your profile page, click the Edit Profile button; this takes you to the Edit Profile & Settings Page.
3) Once here, click on the Settings tab;
4) Near the bottom of the page, you'll find the option for Smiles Default. When this is set to Enabled, plain text like :) will convert to a smiley image. When set to Disabled, plain text in the post will not convert to smiley images.
5) When you are finished, click the Save Account Settings button. This change takes effect immediately.