mssfldt - 11:15 pm on May 12, 2011 (gmt 0)
there are allways four points to be checked:
1. Can the robot index your images (robots.txt)? [yes]
2. Can the robot find your images? (is the url of the image in the html-source-code? )
3. How often visit the imagebot your pages? Usually: the more frenquently you upload new images the higher is the crawling-rate. In my experience: if you upload every week a new pivture it took about 2 weeks until new images are indexed. If you upload one per day it took about two days. (Long term) frequency is an important signal for the bot.
4. Perhaps your images are indexed but you didn't see them. Have you checked the "safeSaerch-Filter"? Make an image-search for "site: yourdomain.tld" and the switch between "Filter: moderate" and "Filter: Off".