I went through exactly that process earlier this week, i.e. purchased a new X25-M 160GB with the 2G firmware and first upgraded to the 2H firmware. Did not have any problems and running Windows 7 Enterprise just fine.
Could you tell us detailed configurations of your system? I'm wondering if you are using AHCI mode, and in that case, which AHCI driver you are using.
I'm curious that if there would be no problems after you run Optimizer on your ssd, but for now I wouldn't ask you to try...
Am using a stock standard Lenovo Thinkpad X61 Tablet, further details in the other post (02H Poll).
After upgrading the X25-M firmware, did a fresh install of W7 (32-bit) and updated all patches, both Microsoft as well as Lenovo (via System Update 4.0 tool).
I didn't "run Optimizer" since no need to do so manually under W7.