In Windows 7 64 bit version of Tixati 2.12, every second Tixati allocates an additional 1.5MB of memory.  Once memory reaches 400MB, Windows 7 64 bit becomes unresponsive or extremely non-responsive.  It looks like sometimes the memory goes up to 400MB then drops back down to 75MB then gets up to 400MB until eventually it stops refreshing the memory and untimely freezes the computer.

I'm running Tixati 2.12 on Windows 7 64bit.  Tixati is steady at 968MB.  No problems whatsoever.

I'm not saying you're not having a problem.  But it's obviously not the same for everyone.  I would suggest that there is some other variable at work here.