Graphing Vlookup as NA() X Axis Problem

[billy_the_kid]

I'm trying to graph a vlookup column where the non-values are coded with NA() so that they do not plot. When I add the data series to the graph if plots properly; however, it skews the x axis (a date/time combo format) and will not let me set date/time before a certain value (e.g. the x axis max. becomes 12/8/09 05:00 instead of the programmed 12/8/09 02:00).

Has anyone experienced anything like this before. I originally thought it was an issue with graph templates, but that no longer seems to be the case. The problem occurs/disappears as I add/remove the vlookup data series.

I have tried copying just values and format of the vlookup series and then plotting and it gives me the same problem with the x axis.

Thanks!