Low memory issue is really annoying. It mostly happens with chinese wince devices and from my experience it doesn't really matter if device has 64/128/256 MB RAM. It may happen in all variations. It's interesting that I never experienced memory error on any of the Mio devices (ex. really old models) as they handle iGO Primo surprisingly smooth. I get this error mostly on unbranded Chinese devices. Luckily in all my cases this sys entry solved such problems:

[debug]
max_memory=55000000
reserve_memory=2097152