I'm not sure what Yoper uses as it's default filemanager/desktop environment. However, I am guessing it's something slow and bulky. First thing to do is try something faster. I LOVE one called gentoo:
http://freshmeat.net/projects/gentoo/?topic_id=860
Second, how is the drive mounted? This may be part of the slowdown process. IF the drive is getting mounted as the filemanager is getting pulled up, then there may be delay there. Please post your /etc/fstab file so we can see how that's getting mounted. If you are selectively mounting it every time with the mount command, that's fine. But you will lose some time simply from doing that. You maybe want to have it mounted at startup.
Also, I am a bit confused. You've got a dedicated HD with ReiserFS that has IDENTICAL files as a dedicated HD with NTFS? Is this simply so win can read it? Anyway, I am wondering which one you are trying to mount, and maybe for some clarification on this.
Cool