Ecstasy+Alcohol=Memory loss?

[i like wimmins]

This has happened 3 times now. I generally start off an evening by drinking, then move on to the chemical entertainment, but I have experienced an unpleasant phenomenon and was wondering if anyone else has. If I'm very drunk, then I take my pills, I get what I've been calling a "memory wipe" - whereby after the E has worn off, I find that I have absolutley zero recollection of anything that happened during the high, or even feeling the high itself. This happened to a friend of mine also, who got trashed, flipped, then the next morning was walking around asking about the location of her pills.
I realize booze makes you forget stuff, but I've been drinking for a while and I know what it feels like to not remember from alcohol; this is different, its like a big fat section was cut out of my brain somehow. And this doesn't come from being black out drunk before hand, just reasonably, enjoyably drunk.
Anyone else experienced something like this? Anyone have any insight?
Thanx.