Psychology in the time of Freud was occupied with dreams. Relaying these to one's analyst was an important part of treatment.
Fast-forward to less than 100 years later, and we know so much about the importance of sleep in consolidating memories during REM  and slow-wave sleep  (among countless other references I have omitted).
Let us assume dreaming is largely relegated to REM (ignoring dreams experienced during stage 2 sleep). If we recall our dreams at a later time then is it detrimental to any subsequent process of memory consolidation?
If our dream represents a state through which our brain is passing to consolidate memory, what is the effect of recalling that intermediate state and potentially storing it back in long-term memory?
Ishikawa A, Kanayama Y., et al (2006). Selective rapid eye movement sleep deprivation impairs the maintenance of long-term potentiation in the rat hippocampus. Eur J Neurosci.,24 (1),243-8.
Louie K, Wilson MA. (2001). Temporally structured replay of awake hippocampal ensemble activity during rapid eye movement sleep. Neuron,29 (1),145-56. FREE PDF
Ji D, Wilson MA (2007) Coordinated memory replay in the visual cortex and hippocampus during sleep. Nat Neurosci, 10(1),100-7. FREE PDF