Major Description
There's a bug on FormBean.getValueFromPrimaryKey() method that's preventing it from correctly restoring an object from the source collection if the user didn't supply a converter. The bug is just an unfortunate type, that resulted in a map lookup for the map itself 
Attached goes two patches: forbean-minimal.diff is a "minimum changes" patch – in only fixes the mentioned bug. forbean.diff fixes a few other (minor, stylistic) issues I've found when editing the affected class in IDEA: it fixes the mentioned bug, remove a couple of unused private methods, and inlines a local variable that's imediately returned – feel free to pick which patch to apply.