GMATPrep # 1 under bad conditions - help to evaluate

Hello all,
I've been a long time lurker around here but haven't had the opportunity to post much (sorry ) however i really do appreciate this forum's quality and hope to be a contributer in the latter stages of the mba process (post-GMAT that is).

I've read a number of posts on the meaning/relevance/representation of the gmatprep and other CAT's, but i would like to have some insight on my results.

I took the gmat prep test 1 last night under the following conditions:
- i work on a macbook pro laptop so i had to dig out a compaq laptop i bought back in 2001 to run the gmat prep software
- this PC is in a terrible state: takes forever to load, to confirm each question i am faced with the hourglass cursor for anywhere between 30 and 45 seconds. Very frustrating.
- the battery is defective and does not charge, so the laptop needs to be plugged in to a socket in order to run (think desktop pc)
- i currently reside in a country where power outages occur around 2-4 times a day (see what i'm getting at? )

Yesterday, electricity was behaving well (not a single power cut) so i decided to take my 1st gmat prep at 9pm - this is after all day study with PR CAT in the morning, needless to say I was tired.
Cut to verbal question #24, BAM!, just like cinderella, power goes out at midnight sharp! I cry myself to sleep.
I wake up this morning and am pleasantly surprised that the software kept track of my progress (great!) but i finish off the exam just to finish the bugger, so cup of coffee in hand, listening to music, i navigate myself through the last questions, my 7 year old pc churning its last churns. (btw another power cut happened somewhere along the line).

Before I reveal my score, i have to say that during the test i was not feeling confident, i was tired, i found the math to be difficult, i wasn't doing good. My preparation consists of, for test-taking strategies, PR2008, and all problems in OG11 and OG Quant review. I have been doing quite well with the OG problems but the gmatprep still seemed harder.

CAT scores so far:
PR 1: 560 Q39 V28
PR 2: 570 Q40 V28
PR 3: 650 Q39 V41
and now...
GmatPrep 1: 690 Q45 V39

I do not get it. I had 15 out of 37 incorrect in Q (whereas in PR CAT, 6-8 wrong) and 9 out of 41 incorrect in V. Worst ratio of wrong to ratio since beginning of prep.
I'm concerned about this Q score, did i get all the experimental questions wrong? (do they exist in gmat prep?) in addition i did see 2 or 3 questions from OG. Could it be a hardware/software glitch.
Oh and I'm scheduled for the test next friday 18th and i'd be ecstatic with a 700...

Sorry for the long post, i would appreciate any opinions on this.
Thank you.