To expand upon this idea, try manually entering observation points then exporting them as a dat file, to understand how the data is represented in that file and edit them accordingly in text editor or spreadsheet software. The biggest issue with the dat file format is that you must maintain a specific number of characters for each column. I have a macro in Excel to export dat files properly so FEFLOW can use them, allowing me to adjust labels, confidence intervals, slice number, node, etc. to 600+ observation points easily.
If you have software to open shape files, this works too, as shape contain more than just X Y and your observation, unlike the rest of the available formats for importing/exporting.
I'm assuming this problem with importing multiple properties of observation points will be resolved with 6.2.
