ok, I tried to duplicate your problem, and I think your problem is the decimal point.

`Option Explicit`

Sub Example_AngleFromXAxis()

' This example finds the angle, in radians, between the X axis

' and a line defined by two points.

Dim pt1(0 To 2) As Double

Dim pt2(0 To 2) As Double

Dim retAngle As Double

pt1(0) = 2: pt1(1) = 5: pt1(2) = 0

pt2(0) = 5: pt2(1) = 2: pt2(2) = 0

' Return the angle

retAngle = ThisDrawing.Utility.AngleFromXAxis(pt1, pt2)

retAngle = RtoD(retAngle)'***** added by cmdrduh

' Create the line for a visual reference

'***** added by cmdrduh

Dim intretangle As Integer

intretangle = CInt(retAngle)

Select Case intretangle

Case 0

MsgBox "0"

Case 315

MsgBox "315"

End Select

' end of ***** added by cmdrduh

Dim lineObj As AcadLine

Set lineObj = ThisDrawing.ModelSpace.AddLine(pt1, pt2)

ZoomAll

' Display the angle found

MsgBox "The angle in radians between the X axis and the line is " & retAngle, , "AngleFromXAxis Example"

End Sub

'***** added by cmdrduh

Private Function DtoR(d As Double) ' Degrees to Radians

Const PI = 3.14159265

DtoR = (PI * d) / 180

End Function

Private Function RtoD(r As Double) ' Radians to Degrees

Const PI = 3.14159265

RtoD = (180 * r) / PI

End Function

this function came out of help, and I added the select case part. I could not get it to find the 315 degree line, til I used CInt() to convert the double to and integer. You could probably do something similiar, or broaden your select case