CL Variable being changed by called CL program

Ladies and Gentlemen, I have a CLLE program with a variable defined as *DEC and 
length 9 0.  This variable is initialized to 0 when the program starts using a 
CHGVAR statement.  Another CLLE program is called that changes a *CHAR variable 
with length 1 to a blank.  This *CHAR variable is not a parameter into the 
second program, nor is the *DEC variable from the first
passed to the second.  Nevertheless, when the second program changes the *CHAR 
variable to blank, the *DEC variable is also changed, causing a decimal data 
area in the calling program when the *DEC variable is used.  The activation 
group used for either program does not appear to be an issue.  The *DEC is used 
as a parameter for a third program that's RPGLE, which may or may not be a 
factor. 

A search of the archives and IBM Fix Central have yielded no results.  We are 
one cume behind on PTFs for V5R2.  IBM would like us to apply the cume first 
but the last cume we applied cost us many thousands of dollars in new hardware 
(long story).  Anyone have any idea what is happening?  Can anyone suggest a 
specific PTF?

Any help will be greatly appreciated. 

Donald R. Fisher, III
Project Manager
Roomstore Furniture Company
(804) 784-7600 extension 2124
DFisher@xxxxxxxxxxxxx