well, he claims to be using cvs
anyway, it was fixed in rc4a, not rc4b since that release never happened xD
but back to the topic, i suspect you have either an outdated zlib library or a corrupted one.
Please check that. Since your the only aMule user having such problem, I very much suspect it's on your side

Greetings!
P.S.: This thread isn't finished. you can keep asking if yuo have more questoins about this problem you are suffering. there aren't much ubuntu users around hehe
Btw, check the aMule rc7 ubuntu package yuo can find in this forums in the "aMule rc7 released" thread (page 4).
One last note: maybe you compield aMule but are lanchng the old rc4a version that is still there? check this too.