diff -ur atanks-orig/src/player.cc atanks/src/player.cc
--- atanks-orig/src/player.cc	2005-08-18 22:02:59.000000000 -0400
+++ atanks/src/player.cc	2005-08-18 22:05:58.000000000 -0400
@@ -1009,12 +1009,12 @@
 		if (weapNum >= RIOT_CHARGE && weapNum <= RIOT_BLAST) {
 			// add points only within range and above ctank
 			if (	(cy > ctank->y - (radius / 2)) ||
-				(abs (ctank->x - cx) > radius))
+				(fabs (ctank->x - cx) > radius))
 				continue;
 		} else if (weapNum >= SML_ROLLER && weapNum <= DTH_ROLLER) {
 			// Only aim rollers above other tanks
 			if (cy > tankY + TANKHEIGHT &&
-				abs (ctank->x - cx) > radius)
+				fabs (ctank->x - cx) > radius)
 				continue;
 		} else if (weapNum >= SML_LAZER && weapNum <= LRG_LAZER) {
 			// Lazer can only be aimed above horizontal
@@ -1085,7 +1085,7 @@
 			if (itemNum  >= ITEM_VENGEANCE && itemNum <= ITEM_FATAL_FURY) {
 				// add sqrt distances for each tank * potential damage
 				long int totalEffectiveDamage = calcTotalEffectiveDamage (itemNum);
-				_targetMatrix[(int)ctank->x] += sqrt (abs (ctank->x - ltank->x)) * totalEffectiveDamage;
+				_targetMatrix[(int)ctank->x] += sqrt (fabs (ctank->x - ltank->x)) * totalEffectiveDamage;
 
 			}
 		}