In 3.107a version i got randomly "Out of memory" alert from CM when it's crunching a dat with 142105 entries (crc32/md5 checksums) in rebuild mode. Previous versions did work correctly. Main memory in my pc is 1,25 GB, XP with SP2. Returned error is showned with many process (20 or above) or few (10 or 11). CPU's usage is always at 40%/45%.
Easy answer....You got too less memory. It's not a memory leak at all.
You most likely have a file listed in the datfile which size is bigger than your available memory and you got the 'Auto' rebuilder advanced option enabled for "memory used for no recompress". The max limit for this 1GB and most likely this isn't available on your system.
Turn off the auto checkbox and set a low value for the MB edit box.
If you still get random issues like that, your system is f****d up. Nothing has changed in memory management for like 2 years or something.