XTEST is failing to send mouse events sometimes

[realales]

Hi everybody,

I'm using XTestFakeButtonEvent(args)
and pass there some numbers like 1, 2, 3, 4, 5. That works fine everywhere.
But once I tried to pass 6 and 7 in then it just work silently and no 
event is actually happen.
That happens on Suse9.3. Here is the xdpyinfo output (cut) for that machine:
----
version number:    11.0
vendor string:    The X.Org Foundation
vendor release number:    60802000
X.Org version: 6.8.2
----

Furthermore, I have another Linux (ubuntu6.06) installation on the same 
machine and XTEST works fine there with 6 and 7 buttons.
xdpyinfo says following (cut):
----
version number:    11.0
vendor string:    The X.Org Foundation
vendor release number:    70000000
----
BTW, in both cases XTestQueryExtension(args) returns the same version : 
2(both minor and major).

So, I wonder if the version of XOrg is the reason of that difference?

I'm looking on XTest.c source to get the answer why BUTTON6, 7, etc. are 
not posted to the system with
XTestFakeButtonEvent(params)
(got XTest source from here:
http://www.cs.wisc.edu/~vg/cgi-bin/lxr/http/source/lib/Xtst/XTest.c#L195 )

Seem it just uses xorg API:
http://www.codase.com/search/relation?namec=xtestfakeinputreq
But its not very clear what happens next in there.

Does anybody could clarify that a little?
Is it a defect with xorg version 6.8? Did it fixed or it's just an issue 
with configuration?
I also should say that my mouse successfully generates all mouse events 
if I use it manually. The problem is only with XTestFakeButtonEvent.
Kind regards,
  --Andrei