The Images folder is reserved for Sitefinity, but you are free to use any other name for your custom images folder.
Can you give me more information about your master page and setup? Also please try using:
"my alt text"
the Telerik team
Do you want to have your say in the Sitefinity development roadmap? Do you want to know when a feature you requested is added or when a bug fixed? Explore the Telerik Public Issue Tracking
system and vote to affect the priority of the items