Is Professional LOR from current employer better than previous employer

Hello there

I am yet to take the professional LOR from my current employer.I have got a yes from my previous employer for a professional .I quit the previous company in October 2011 and now since December 2012 joined this new company.I have few questions regarding this issue.

Will there be any problem with my profile with the professional LOR being from my previous employer??

Will the University's shortlisting committee downplay or give a negative for getting a professional LOR from previous employer rather than current one.

Is a Professional LOR from the current employer more important/valued than the previous employer.

Please let me know as I am in total dilemma whether to ask a professional LOR from my current employer.

If one thinks this could be some way detrimental to my career please suggest a few ideas so that I can get a professional LOR from my current employer without causing any disappointment/damage.

Thanks well in advance