Reasons for elevated/paretic diaphragm? Serious?

Please excuse my English - must translate my thoughts as I write! :-)

Does anyone have a possible explanation for the following?

Since January-February: Elevated diaphragm, atelectases - total lung capacity 55 %, restrictive breathing pattern and paradoxical breathing movements. O2-sat 94-95. I strongly believe the number I saw for total lung volume was 1,7 l.
Broncoscopy showed nothing, no mucus, tissue seemed healthy, nothing showed up on tests for bacteria or fungus. Blood pressure fine.
Sniff test showed reduced movement in right diaphragm, contrast CT of chest gave nothing further. Extensive bloodwork done, the only abnormal findings so far are elevated CRP (17) and Hb lower than what is normal for me.  Next up is MR Columna and CT of abdomen and pelvis. I am also waiting for appointment for neurophysiologic examination - Electromyographi?

I am a woman, 43, smoker - have been for years. BMI 32,sth...
Had a lumbal laminectomy/fixation done in December, and it was when slowly being able to walk a little longer I started noticing the breathing problems and that my asthma medication didn't work.
Diagnosed with sero-negative HLAB27-positive inflammatory arthritis 8-10 yrs ago, taking NSAIDS and Sulfasalazine for this.
Allergies and mild asthma since childhood, just switched from Seretide to Symbicort for this in addition to Bricanyl.
I probably have irritated bowel syndrome or something, needing the toilet 2-6 times daily.
Sister with ankylosing spondylitis, niece with Cystic Fibrosis, daughter with Coeliac Disease. Most women in close family (myself included) have migraine.
No significant weightloss since breathing problems started, except what could be expected after the back surgery and exercise since. No problems with appetite.
My muscles cramp very easily and very often, all over, but I also build muscles easily.

I feel I am being taken very good care of at the outpatient clinic at a Norwegian hospital, but am anxious to find out more about both possible reasons and the degree of seriousness of my breathing problems. (Have stopped freaking out about it and feel quite calm and relaxed about it, but still curious.)
Everywhere I read how elevated and/or paretic diaphragm on ONE side shouldn't give any symptoms, so why can I barely climb the stairs or get dressed, and even worse - hardly play with or walk my dog?

[Kironi]

Oh, and last week I was given a PEP (Positive Expiratory Pressure?) device which I was told to breath trough 3X10 times, 3-4 times a day. This was an attempt to reopen the collapsed parts of the lung.(?) However, it seemed to make me worse instead of helping the situation. Strange...