diff --git a/wled00/FX.h b/wled00/FX.h
index d52bcc2b..413b87cd 100644
--- a/wled00/FX.h
+++ b/wled00/FX.h
@@ -565,9 +565,9 @@ typedef struct Segment {
     inline bool     hasRGB(void)         const { return _isRGB; }
     inline bool     hasWhite(void)       const { return _hasW; }
     inline bool     isCCT(void)          const { return _isCCT; }
-    inline uint16_t width(void)          const { return isActive() ? (stop - start) : 0; }         // segment width in physical pixels (length if 1D)
+    inline uint16_t width(void)          const { return (stop  > start)  ?  (stop - start)  : 0; } // segment width in physical pixels (length if 1D)
     inline uint16_t height(void)         const { return (stopY > startY) ? (stopY - startY) : 0; } // segment height (if 2D) in physical pixels // WLEDMM make sure its always > 0
-    inline uint16_t length(void)         const { return width() * height(); }     // segment length (count) in physical pixels
+    inline uint16_t length(void)         const { return width() * height(); }     // segment length (count) in physical pixels // WLEDMM fishy ... need to double-check if this is correct
     inline uint16_t groupLength(void)    const { return max(1, grouping + spacing); } // WLEDMM length = 0 could lead to div/0 in virtualWidth() and virtualHeight()
     inline uint8_t  getLightCapabilities(void) const { return _capabilities; }
 
diff --git a/wled00/FX_2Dfcn.cpp b/wled00/FX_2Dfcn.cpp
index e803b56d..57612247 100644
--- a/wled00/FX_2Dfcn.cpp
+++ b/wled00/FX_2Dfcn.cpp
@@ -252,11 +252,12 @@ void Segment::startFrame(void) {
   _isSuperSimpleSegment = !mirror && !mirror_y && (grouping == 1) && (spacing == 0); // fastest - we only draw one pixel per call
 
 #ifdef WLEDMM_FASTPATH
-  _isValid2D  = isActive() && is2D();
+  //_isValid2D  = isActive() && is2D();
+  _isValid2D  = isActive() && strip.isMatrix && length() > 1;
   _brightness = currentBri(on ? opacity : 0);
   // if (reverse_y) _isSimpleSegment = false; // for A/B testing
-  _2dWidth    = is2D() ? calc_virtualWidth() : calc_virtualLength();
   _2dHeight   = calc_virtualHeight();
+  _2dWidth    = _isValid2D ? calc_virtualWidth() : calc_virtualLength();
   _virtuallength = calc_virtualLength();
   #if 0 && defined(WLED_ENABLE_HUB75MATRIX)
     _firstFill = true; // dirty HACK
@@ -300,9 +301,9 @@ void IRAM_ATTR __attribute__((hot)) Segment::setPixelColorXY_fast(int x, int y,
   #endif
   if (simpleSegment) return;   // WLEDMM shortcut when no mirroring needed
 
-  // handle mirroring
-  const int_fast16_t wid_ = stop - start;
-  const int_fast16_t hei_ = stopY - startY;
+  // handle mirroring - minimum width/height is 1 !!!
+  const int_fast16_t wid_ = max(1,stop - start);
+  const int_fast16_t hei_ = max(1, stopY - startY);
   if (mirror) { //set the corresponding horizontally mirrored pixel
     if (transpose) strip.setPixelColorXY_fast(start + x, startY + hei_ - y - 1, scaled_col);
     else           strip.setPixelColorXY_fast(start + wid_ - x - 1, startY + y, scaled_col);
@@ -364,8 +365,8 @@ void IRAM_ATTR_YN Segment::setPixelColorXY(int x, int y, uint32_t col) //WLEDMM:
   }
 
   const uint_fast16_t glen_ = groupLength(); // WLEDMM optimization
-  const uint_fast16_t wid_ =  width();
-  const uint_fast16_t hei_ = height();
+  const uint_fast16_t wid_ = max(uint16_t(1), width());
+  const uint_fast16_t hei_ = max(uint16_t(1), height());
 
   x *= glen_; // expand to physical pixels
   y *= glen_; // expand to physical pixels
diff --git a/wled00/FX_fcn.cpp b/wled00/FX_fcn.cpp
index 8f28daf7..a735bdc4 100644
--- a/wled00/FX_fcn.cpp
+++ b/wled00/FX_fcn.cpp
@@ -899,7 +899,7 @@ uint16_t Segment::calc_virtualLength() const {
 #endif
   uint16_t groupLen = groupLength();
   uint16_t vLength = (length() + groupLen - 1) / groupLen;
-  if (mirror) vLength = (vLength + 1) /2;  // divide by 2 if mirror, leave at least a single LED
+  if (mirror && width() > 1) vLength = (vLength + 1) /2;  // divide by 2 if mirror, leave at least a single LED // WLEDMM bugfix for pseudo 2d strips
   return vLength;
 }
 
@@ -1115,7 +1115,7 @@ void IRAM_ATTR_YN __attribute__((hot)) Segment::setPixelColor(int i, uint32_t co
       // we have a vertical or horizontal 1D segment (WARNING: virtual...() may be transposed)
       int x = 0, y = 0;
       if (virtualHeight()>1) y = i;
-      if (virtualWidth() >1) x = i;
+      else if (virtualWidth() >1) x = i;
       setPixelColorXY(x, y, col);
       return;
     }