Believe it or not, the issues I have with rtorrent are caused by a HARDWARE problem. I tried pointing a big household fan to my modded GP+, and guess what, rtorrent stopped failing hashes. I hashed a big 60+ GB torrent and worked perfect. It looks like the mod I have done to my GP+ isn't enough to warm the device

. I'll have to add a little fan

.
The weird thing is everything (including aMule, md5sum, etc) excepting rtorrent is working without the need of addittional cooling. Dunno why this program is more sensitive to heat problems.