Why doesn't the ENC28J60 work with the CD4050BE?

Quick question, perhaps?

I have been playing around with arduino's and SD cards, in the process I have been instructed to use a level shifter to avoid damage to the SD card, specifically the CD4050BE.

I then thought about the ENC28J60 breakout I was using and how this chip is also 3.3v (although supposably 5v tolerant). So I figured that I should be wiring up the ENC28J60 via the CD4050BE level shifter too, but for some reason this simply don't work.

Can anyone enlighten me as to why the ENC28J60 doesn't seem to work when level shifted with the CD4050BE?

Also, if I want to use both the ENC28J60 and the SD card on the same arduino, is it simply a case of ensuring that they have different chip select pins?

Thanks in advance!

1st question, don't know. I think CD74HC4050 (TI spoecific) or 74HC4050 is the intended chip tho: http://www.digikey.com/product-detail/en/CD74HC4050E/296-9213-5-ND/376792

You'll note there aren't any test conditions with Vcc = 3.3V here: http://www.ti.com/lit/ds/symlink/cd4049ub.pdf

Where as 74HC4050 is specifically tested with Vcc down at 2V and 4.5V, so Vcc = 3.3V is within the norm of expected operation.

http://www.ti.com/lit/ds/symlink/cd74hc4049.pdf

2nd question, yes, separate CS pins, only 1 low at a tme.