Jpan that link you provided is not relevant, sleep paralysis is well understood, a couple instances of sleep paralysis is nothing to worry about, and perfectly normal, according to Wikipedia's various studies have been done that show 20-60% of people have experienced sleep paralysis at least once in their life. Some people have chronic issues with it, however there is no underlying medical condition associated with it the link you refereed to is for medical reasons for paralysis, sleep paralysis is psychological in nature and unrelated, it's actually a required state that we all go through during a normal sleep cycle, it prevents us from thrashing around or getting out of bed during REM sleep (sleep walkers skip the paralysis step)
I've had some interesting experiences with odd dream states, similar to TCMTech's mine were probably triggered by the mental changes that the death of my mother and loss of my son in the last two years have upset my sense of a stable world, these kinds of changes are part of an adult mind that's set in it's ways encountering fundamental changes like death or other drastic life changes. I wouldn't worry about it in the slightest unless it progress past a few occasional episodes, always worth talking to a doctor about these kinds of things but the drastic medical problems that can be associated with paralysis is by far 'jumping the gun'
Transistor, for further reading check out Lucid Dreaming on Wikipedia, it's a field modern psychologists are studying actively in attempts to further refine our understanding of consciousness because to be blunt about it the medical and psychologist communities don't have the slightest clue what consciousness really is.
Due to intermittent insomnia I've had my entire life I've grown to use these times of mental unrest while the body is supposed to be idle as fertile ground to experiment with understanding the nature of my own consciousness in a self exploratory way, it's quiet eye opening coming to terms with the fleeting nature of our own minds, thoughts and their connection with the real world, if you explore the boundaries between wakefulness and sleep you gradually learn just how ephemeral the real word is.
I definitely recommend checking it out if you're curious because test subjects prone to lucid dreaming experiences have been able to actually go from a state of wakefulness directly into a dream state without losing consciousness and can communicate with psychologists through the use of eye movements (eye movements in a dream track with the real eye's movement because the eye is hardwired to the brain outside of the normal motor cortex)
I haven't been able to reproduce the Lucid dreaming state I had a few months ago (I had one when I was about 12 as well) but I have been able to generate some incredible visual images during the Hypnagogic stage of sleep, it's a lot of fun and the sensation of consciousness drifting in and out during the tail end of the hypnagogic stage is rather interesting. Keeping concious while the brain shifts into REM sleep itself has so far eluded me, but there are techniques that are supposed to help, such as eye monitors to determine when REM sleep is obtained to produce an audio tone that's supposed to remind you that you're dreaming to help bring the conscious awareness into the REM state. But it 's also something you can only play around with once or twice a day =) So a hard thing to study.
There is promise though that increased understanding of consciousness and the sleep state in general will eventually lead to being treatment for some forms of sleep issues, such as night terrors, a lot of ground is being gained, but it's not something we'll probably ever have true breakthroughs in, it's too dependent upon the individual.