diff --git a/.gitignore b/.gitignore
index 55f4c5301..959e7c104 100644
--- a/.gitignore
+++ b/.gitignore
@@ -64,6 +64,5 @@ config.log
 *.pyc
 site_scons/site_tools/mfprogram/*.pyc
 site_scons/site_tools/gch/*.pyc
-others*
 
 screenshot_*
diff --git a/src/simulation/Simulation.cpp b/src/simulation/Simulation.cpp
index 87743df71..30364201b 100644
--- a/src/simulation/Simulation.cpp
+++ b/src/simulation/Simulation.cpp
@@ -2187,7 +2187,13 @@ int Simulation::eval_move(int pt, int nx, int ny, unsigned *rr)
 		}
 		else if ((r&0xFF) == PT_INVIS)
 		{
-			if (pv[ny/CELL][nx/CELL]>4.0f || pv[ny/CELL][nx/CELL]<-4.0f)
+			float pressureResistance = 0.0f;
+			if (parts[r>>8].tmp > 0)
+				pressureResistance = (float)parts[r>>8].tmp;
+			else
+				pressureResistance = 4.0f;
+
+			if (pv[ny/CELL][nx/CELL] < -pressureResistance || pv[ny/CELL][nx/CELL] > pressureResistance)
 				result = 2;
 			else
 				result = 0;
@@ -2328,7 +2334,12 @@ int Simulation::try_move(int i, int x, int y, int nx, int ny)
 			}
 			else if ((r&0xFF) == PT_INVIS)
 			{
-				if (pv[ny/CELL][nx/CELL]<=4.0f && pv[ny/CELL][nx/CELL]>=-4.0f)
+				float pressureResistance = 0.0f;
+				if (parts[r>>8].tmp > 0)
+					pressureResistance = (float)parts[r>>8].tmp;
+				else
+					pressureResistance = 4.0f;
+				if (pv[ny/CELL][nx/CELL] >= -pressureResistance && pv[ny/CELL][nx/CELL] <= pressureResistance)
 				{
 					part_change_type(i,x,y,PT_NEUT);
 					parts[i].ctype = 0;
diff --git a/src/simulation/elements/FRAY.cpp b/src/simulation/elements/FRAY.cpp
index dd590cbff..5b7b016dc 100644
--- a/src/simulation/elements/FRAY.cpp
+++ b/src/simulation/elements/FRAY.cpp
@@ -47,6 +47,11 @@ Element_FRAY::Element_FRAY()
 //#TPT-Directive ElementHeader Element_FRAY static int update(UPDATE_FUNC_ARGS)
 int Element_FRAY::update(UPDATE_FUNC_ARGS)
 {
+	int curlen;
+	if (parts[i].tmp > 0)
+		curlen = parts[i].tmp;
+	else
+		curlen = 10;
 	int r, nxx, nyy, len, nxi, nyi, rx, ry;
 	for (rx=-1; rx<2; rx++)
 		for (ry=-1; ry<2; ry++)
@@ -57,7 +62,7 @@ int Element_FRAY::update(UPDATE_FUNC_ARGS)
 					continue;
 				if ((r&0xFF)==PT_SPRK) {
 					for (nxx = 0, nyy = 0, nxi = rx*-1, nyi = ry*-1, len = 0; ; nyy+=nyi, nxx+=nxi, len++) {
-						if (!(x+nxi+nxx<XRES && y+nyi+nyy<YRES && x+nxi+nxx >= 0 && y+nyi+nyy >= 0) || len>10) {
+						if (!(x+nxi+nxx<XRES && y+nyi+nyy<YRES && x+nxi+nxx >= 0 && y+nyi+nyy >= 0) || len>curlen) {
 							break;
 						}
 						r = pmap[y+nyi+nyy][x+nxi+nxx];
diff --git a/src/simulation/elements/INVIS.cpp b/src/simulation/elements/INVIS.cpp
index f67f3e8a1..e82709854 100644
--- a/src/simulation/elements/INVIS.cpp
+++ b/src/simulation/elements/INVIS.cpp
@@ -48,10 +48,16 @@ Element_INVIS::Element_INVIS()
 //#TPT-Directive ElementHeader Element_INVIS static int update(UPDATE_FUNC_ARGS)
 int Element_INVIS::update(UPDATE_FUNC_ARGS)
 {
-	if (sim->pv[y/CELL][x/CELL]>4.0f || sim->pv[y/CELL][x/CELL]<-4.0f)
-		parts[i].tmp = 1;
+	float pressureResistance = 0.0f;
+	if (parts[i].tmp > 0)
+		pressureResistance = (float) parts[i].tmp;
 	else
-		parts[i].tmp = 0;
+		pressureResistance = 4.0f;
+
+	if (sim->pv[y/CELL][x/CELL] < -pressureResistance || sim->pv[y/CELL][x/CELL] > pressureResistance)
+		parts[i].tmp2 = 1;
+	else
+		parts[i].tmp2 = 0;
 	return 0;
 }
 
@@ -59,7 +65,7 @@ int Element_INVIS::update(UPDATE_FUNC_ARGS)
 int Element_INVIS::graphics(GRAPHICS_FUNC_ARGS)
 {
 	//pv[ny/CELL][nx/CELL]>4.0f || pv[ny/CELL][nx/CELL]<-4.0f
-	if(cpart->tmp)
+	if(cpart->tmp2)
 	{
 		*cola = 100;
 		*colr = 15;
diff --git a/src/simulation/elements/TRON.cpp b/src/simulation/elements/TRON.cpp
index e608f56ee..74b7ee1c3 100644
--- a/src/simulation/elements/TRON.cpp
+++ b/src/simulation/elements/TRON.cpp
@@ -258,7 +258,7 @@ int Element_TRON::trymovetron(Simulation * sim, int x, int y, int dir, int i, in
 //#TPT-Directive ElementHeader Element_TRON static bool canmovetron(Simulation * sim, int r, int len)
 bool Element_TRON::canmovetron(Simulation * sim, int r, int len)
 {
-	if (!r || ((r&0xFF) == PT_SWCH && sim->parts[r>>8].life >= 10) || ((r&0xFF) == PT_INVIS && sim->parts[r>>8].tmp == 1))
+	if (!r || ((r&0xFF) == PT_SWCH && sim->parts[r>>8].life >= 10) || ((r&0xFF) == PT_INVIS && sim->parts[r>>8].tmp2 == 1))
 		return true;
 	if ((((sim->elements[r&0xFF].Properties & PROP_LIFE_KILL_DEC) && sim->parts[r>>8].life > 0)|| ((sim->elements[r&0xFF].Properties & PROP_LIFE_KILL) && (sim->elements[r&0xFF].Properties & PROP_LIFE_DEC))) && sim->parts[r>>8].life < len)
 		return true;