BB Bold 9700 :: HTML Images Don't Download Due To Limited Space

I moved to BlackBerry Bold 9700 about two weeks ago. Everything works great, except for one issue. Images in my HTML email messages don't download. I have tried all combinations of settings on automatically download images and confirm images download, in the Options > Email Settings menu. What happens is: When I hard reset the phone (take out the battery and reinsert it), and then do Get Images, images download. However, this continues only for some 3-4 hours, or say about 10-15 messages. After a point, Get Images doesn't download images. Even the arrows on the top right of the screen, that indicate an attempt to download, don't come. It almost seems like the phone has kept a limited space aside to download images in HTML messages, and this space is filled up and hence it stops downloading. The moment the battery is taken out and reinserted, Get Images works. But again for some time only.Tried taking Vodafone's help. They updated my Service Book, which according to them is the "standard solution" to Images downloading problem. But nothing happened. Which is expected, because they were possibly giving me a solution for images never downloading. In my case, they download for a bit, and then refuse to, till hard reset.Tried finding where any memory related settings could be there. Found a thing in Settings > Memory > Compression. Tried both Enabled and Disabled, it doesn't help.