Hi I've already posted a bug report on the fvwm mailing list some weeks ago regarding this, but no one answered. Today I switched to xorg-7.0.0 and the problem is still there, so it must be fvwm.
The problem I found is related to the composite extension of xorg: when I run xcompmgr (the composite manager) fvwm looses the screen-scrolling abillity to the right and down. I mean, after running "xcompmgr" from the command line, you can no longer scroll (by placing the cursor on the screen edge) to the right or down. And even after killing the composite manager the problem persists. The left and up scrolling work fine. Also, if you restart fvwm, even with xcompmgr running, things go back to normal. So it must be something on the start of xcompmgr... Other wm's work flawlessly. I'm using a patched version of fvwm from the gentoo portage: it has the "translucency" patch applied. So if any of you are using a composite manager and it works ok with the unpatched fvwm, please let me know. Is there anything else I can do to help tracking the bug? Thanks! Cheers