[Q] X10 mini pro (u20i) cant enter flashmode topic

A friend gave me his x10 mini pro to install a custom rom to it with a higher android version.
The custom roms i chose (mincm) requires an unlocked bootloader and stock 2.1.1.x
The device was on 1.8 as i received it.

So i started PC companion to update it, entered flashmode by holding the back button before inserting to usb,
phone entered flashmode and update went through.
At this moment of time the phone was on 2.1X stock Firmware and i went on to the next step unlocking the bootloader.

So now phone is stock 2.1x and unlocked bootloader but it does not enter flash mode anymore.
I think i've tried every possible button combination without success like:
holding the back button
holding all 3 buttons
holding combinations of 2 buttons
doing the above while phone is on and quickly remove and reinsert the battery

Its a X10 mini pro u20i,
Firmware 2.1-update1 (Buildnumber 2.1.1.C.0.0)
2.6.29 Stock Kernel

Phone still works normally aside from not beeing able to enter flashmode (to flash naA kernel).

What else can i try?
As last resort, can you suggest a ROM that runs fine on stock kernel with at least android 2.3?