URGENT: Queries on HSMP (non-JR)visa extension (under Tier1)

Hi Everybody,

I have a HSMP visa (non-JR) which is valid till 23rd May '09. Just started planning my application. Have some queries reg. the same. I tried calling the UKBA customer service and mailed them too.. but no use.. My queries are as follows:

1) When should I apply for the extension keeping the current processing time in mind? Looks like, HO has quite a lot of backlogs for non-JR extension applications and ppl who applied for extension on 10th Jan'09 are getting their visa now (5th March)- which is almost 7 and half weeks.

2) I am bit confused with the 15 month window for past earnings assessment. Would this 15 months period be immediately before the date of application for the visa extension or the actual date of visa expiry? From tier1guidance page 17 (point 82), I think it’s backward from the date of application for the visa extension.
Assuming it to be the date of application, what date to what date will be this window in my case (say if I apply on 17th of April '09)? As per guidance (page 18-point 83), they consider calendar months (eg. 14th Jan – 13th Feb) and not start/end date of a month. So, is it 17th Jan ’08 to 17th Apr ’09 (note this date for calculation, it’s almost mid-month)?

3) My project may end at the end of this month (March). After that I may not have the job. So, will it be a problem if I am not into a job when I apply for the extension?

4) I believe HO considers gross salary (before tax deduction) for accessing past earnings. In that case there is no need to mention the net salary. Right? Or, the net salary needs to be mentioned in the cover letter, so that those can be cross checked with the bank statement/payslips?

Plz help with answer to my queries.

Regards,
Debjani.