It is just me, or is the x-axis slightly off on the FTIR data in the Virtual Organic Lab? For example, the IR of diethyl ether has a peak at around 3040 wavenumbers that is typically reported as being closer to 2990 in the literature. In the same spectrum, the peak at 1130-ish is spot-on, so it’s more like the axis is slightly stretched, particularly between 2200 and 4500 wavenumbers.
I’ve noticed this in many (most?) of the spectra, so I don’t think it’s unique to diethyl ether, but it can make it a bit difficult to distinguish between alkyl C-H bonds and aryl/vinyl C-H bonds, since the “3000 line” is slightly off.