I have been on meds (Truvada/Sustiva) since Spring '06 and undetectable 6 weeks after starting my drug regiment. My CD4 count continues to rise (now 544 vs. 403 at last testing), however, my last results indicated a viral load of 92 vs. <50. My doctor said <50 is ideal and that I was slightly detectable. Does this indicate resistance? I am concerned because I switched to Atripla about 1 week before the blood draw and had a flu shot Pneumonia vaccination 3 weeks prior. Should I be concerned?

I wouldn't be concerned. This is most likely lab variation related to the viral load assay and not a true failure of your regimen. We refer to this as "blipping" and it is quite common. There is a possibility that the vaccinations did cause a slight increase in viral replication resulting in a very low detectable viral load. This is mostly seen in people not on treatment. I would predict that your next result will be undetectable.