[BioC] beadarray - raw data import - bead background intensities faulty

[Felix Engel]

Dear Mark Dunning.

With the latest SVN version of beadarray the background-read problem 
(raw data import) remains, when issuing:

BLData = readIllumina(imageManipulation = "none", 
backgroundMethod="none", textType=".txt")

I still cannot explain resulting background values below zero: There are 
500000 beads with average intensity -215359277, where another 500000 
beads on the array give a normal background (average intensity 630).

Thanks for your insight,

Felix.