I'm trying to flash a Cyanogenmod 7.1.5 on my Motorola Milstone A853. I can access the Bootloader (version 90.74) and started RSDLite 5.7 and used a base sbf file, which flashes normally.
When I reboot the device I can access recovery mode by pressing Camera, but when I access the recovery mode by pressing Volume UP and then press Camera the recovery menu does not open.
I see videos on YouTube, read a lot of tutotials, but I don't know what to do. Is there another way to do this?

Powerbutton selects things, not the camera one. These instructions also seem to indicate that you should use the keyboard's navigation pad. Or are you having trouble getting into recovery to begin with? You first seem to say that you can access it, but then you seem to say that you cannot. – eldarerathis♦ Jul 20 '12 at 14:38