GC: Memory keeps growing

[Chris via Digitalmars-d-learn]

My garbage collected app starts with ~10 MB in memory, however 
with every execution of code it grows by at least 0.2 MB (or more 
depending on the input). Although I can see memory being freed 
(say it goes up to 32 MB and drops to 14 MB), it keeps on growing 
slowly but surely.

I use structs for the most part [1] and reuse arrays at critical 
points, clearing them with destroy() after use. Maybe this is the 
problem? I dunno. I'd be grateful for any hints.

[1] The few classes I use are either singletons or instantiated 
only once and cached when the programs starts.