BootMii-boot2 won't show up

I've used Hackmii installer v0.6 to install BootMii beta 4 to my Wii, installation works fine, boot1 is supported, no error message, files are copied to the SD and 2 blocks of my NAND are updated, no problem here.
When I power on the Wii, the drive led flashes 2 times, but the screen stays black and nothing else happens.
Yes, I've heard about SD compatibility issues and I'm quite sure my "Proline" 2GB SD card is not compatible. My question is :
Wasn't bootmii/boot2 supposed to boot to system menu if something wrong happened ?
Why am I completely stuck in this black screen ?
I've tried tweaking bootmii.ini (changing video from PAL60 to PAL50, i'm in 4.2E on an European Wii) without positive result.
I've been forced to uninstall bootmii (because I've no other cards and it's Sunday, shops are closed).

How did you uninstall BootMii fs you can't boot System Menu?

Anyway, yeah it should boot System Menu if SD card is incompatible. Try removing your SD card and see if that works.

BTW, have you uninstalled BootMii, or are you going to?

The System Menu booted fine with the SD card ejected, so no issue with uninstall.
I gave up and bought another SD card (2GB Sandisk for Wii, the one with the Nintendo seal ;) ).
Then, I re-installed BootMii it and it worked perfectly with that card.
Thanks anyway.