So i've spent the last few days playing with building from CM9 from source and the kernel too.
I've managed to compile both successfully or so it seems.
upon pushing them to the touchpad and attempting to insmod, i get the error "Device or resource busy"
i have done a power off/reboot and hasnt had any effect. I cant find any other information to explain why it wont let me load them now.
i performed a modinfo check on both sierra.ko and sierra_net.ko, and received these details back:
description: USB Driver for Sierra Wireless USB modems
author: Kevin Lloyd, Elina Pasheva, Matthew Safar, Rory Filer
srcversion: C58D9EB6D295B757AA65F22
depends:
vermagic: 2.6.35-palm-tenderloin SMP preempt mod_unload ARMv7
parm: nmea:NMEA streaming (bool)
parm: debug

ebug messages (bool)
i checked this against the included cifs.ko that is standard in the CM9 build and got:
version: 1.64
description: VFS to access servers complying with the SNIA CIFS Specification e.g. Samba and Windows
license: GPL
author: Steve French <sfrench@us.ibm.com>
srcversion: 3E08663B86EDD76112AB79C
depends:
vermagic: 2.6.35-palm-tenderloin SMP preempt mod_unload ARMv7
parm: CIFSMaxBufSize:Network buffer size (not including header). Default: 16384 Range: 8192 to 130048 (int)
parm: cifs_min_rcv:Network buffers in pool. Default: 4 Range: 1 to 64 (int)
parm: cifs_min_small:Small network buffers in pool. Default: 30 Range: 2 to 256 (int)
parm: cifs_max_pending:Simultaneous requests to server. Default: 50 Range: 2 to 256 (int)
so it looks to have compiled correctly and against the correct kernel version.
I've attached the 2 .ko files. hopefully someone may be able to see what is going on there.